For nearly 200 years, the United States continually admitted new states to the Union. But after Hawaii became the 50th state in 1959, expansion halted. Along with America’s broader stagnation, population growth has slowed.

In the 20th century, America defeated fascism and communism. Her hegemony, while marred by myriad missteps, ushered in an era of unprecedented peace, prosperity, and liberty. But if America is to defend her hegemony, she must grow again. Scale is essential for innovation and economic growth and underpins America’s military strength. 330 million Americans simply won’t be able to compete against 1.4 billion Chinese. Globalization and free trade aren’t a substitute for scale either, for they deprive the nation of its autonomy in world affairs.

The solution is for Canada and Mexico to join the Union—i.e., for Canada and Mexico, or their constituent states, to be voluntarily admitted into the United States. America and her institutions are uniquely suited to accommodating this larger and more heterogenous Union and to forging a common political community. The example of German reunification demonstrates that economic convergence is possible too, as I will explain. In addition to reenergizing America, propelling economic growth, and making Americans better off, this would have extraordinary benefits for Canadians and Mexicans too. In particular, tens of millions of Mexicans could be lifted out of poverty.

In his excellent recent book, One Billion Americans, Matthew Yglesias argues for massive population growth as well, though he proposes achieving this through subsidizing fertility and increasing immigration. In practice, these proposals may not rise to the challenge. If the choice America faces is between decadent decline or renewed growth, an expanded Union may be our best bet for the latter.

To be clear, I realize that this is a somewhat crazy idea. So don’t take take this essay as a wholesale endorsement of the proposal. But I do think it is an idea worth exploring—if only for the sake of expanding our conception of the possible. I invite you to explore it with me.

Bigger is Better

A central concept in growth economics is that of “increasing returns to scale”: essentially, bigger is better. A larger population and a larger market benefits all.

A larger population enables more innovation. More people means there are more creative minds with new ideas and inventions. In turn, more people means more customers, so a new invention is more profitable, incentivizing firms to invest in research and development. This drives economic growth.

A larger market also enables more specialization. One city can focus on developing software, another on manufacturing cars, a third on financial services. This specialization makes firms and workers more productive, again driving economic growth.

Think of it this way. A small country would struggle to support an ambitious space program; the cost would be too high. But a large country can support an ambitious space program; distributed over a large population, the cost per person is manageable. The same principle applies to things like medical research, technological development, and military investment.

This logic of increasing returns to scale underpinned much of the economic case for globalization. The free exchange of goods and people would make us all better off, the high priests of economics told us. And they were right! We can all enjoy Silicon Valley’s software and Germany’s cars. A German-American pharmaceutical collaboration, headed by Turkish and Greek immigrants, recently created the first vaccine shown to be effective against Covid-19. The gains to scale through globalization have been extraordinary.

The Autonomy of the Political Community

So, then, the solution to the quest for scale is globalization? We don’t need a larger America after all—free trade agreements like NAFTA are enough?

The problem with globalization is that it deprives the political community of its autonomy—particularly in that most essential realm of war and peace. The nation can no longer determine its own destiny, but rather becomes dependent and vulnerable and subject to whim of others.

For instance, as the American establishment has become clearer-eyed about the rise of authoritarian China, they have suddenly realized that maybe, just maybe, outsourcing much of America’s manufacturing there was a bad idea. If the Chinese acted on their expansionist ambitions, would America be able to push back—or would we be cowed by the cutoff of the supply of new iPhones and a tanking stock market?

Even trade with allies who purport to share our values is questionable in this regard. If push came to shove and a general war broke out, could America really rely on the German industrial base to start mass producing weapons? Honestly—probably not. America prevailed in WWII because she could mobilize her epic industrial might to produce an “arsenal of democracy.” If America were once again to find herself in an existential struggle, I fear she would not be able to pull off that same feat again.

This deprival of the political community’s autonomy is what so many Europeans despise about the European Union. While the cosmopolitan elite may identify as “European,” first and foremost most Germans still think of themselves as German, most French people still as French, and most Britons still as British. Their political community is their nation, not the EU. So when an EU technocrat—someone they didn’t elect, much less identify with—tells them how to live their lives, they rebel.

This has led to an instinct of retrenchment and a push to reverse globalization, most famously Trump’s trade wars. What this gets right is how interdependence has undermined America’s independence. If America can’t defend her core interests and values because she is entirely dependent on others, her hegemony becomes a farce.

What this gets wrong is that America, alone, with its puny 330 million people, will not be able to compete. America’s hegemony rests on her economic might, sustained by her roaring engine of innovation. America’s economy in turn supports her dominant military. But without the benefits of scale, America will not be able to sustain her economic primacy. 1.4 billion Chinese will be able to outpace and out-innovate 330 million Americans if they try go it alone.

Without scale, America will decline; her hegemony will wither. But increased scale through globalization robs America of her freedom to act; her hegemony become toothless. How, then, to square the circle?

There is one possibility. Rather than enmeshing America with foreign countries, make America itself bigger! Enlargen the political community! A bigger nation can enjoy the innovation and specialization made possible by scale. But it also retains its autonomy. Though larger, the nation is still a coherent political community that can determine its own fate.

Arguably, this is what America has always done. It expanded from one coast to another and rapidly grew its population. That’s how America became the hegemon in the first place, replacing the smaller British. But America now stagnates: her territory fixed, her population growing ever-more slowly, ultimately unable to keep pace with the world’s rising powers. If America wants to preserve her hegemony, she must grow again.

Growing America

A bigger America is exactly what Matthew Yglesias argues for in his excellent recent book, One Billion Americans. Yglesias envisions this growth occurring through increased fertility and immigration—with the goal of, as the title indicates, a population of 1 billion. Directionally, this is sound. But, realistically, Yglesias’s proposals won’t get us anywhere close to the massive population growth he imagines.

America’s birth rate is already substantially below the replacement level. We could count ourselves lucky if Yglesias’s suite of proposed pro-natalist policies even got us back to replacement. Extensive family benefits like the ones he proposes have been tried in Europe, and they haven’t yielded a massive baby boom.

Similarly, America could definitely accommodate—and benefit from—significantly increased immigration. But I think Yglesias underestimates the political challenge of bringing in the requisite number—hundreds of millions—of immigrants. Sure, theoretically, we could raze our cities and build a sea of skyscrapers in their stead to accommodate the newcomers. But the forces of NIMBYism in America are already so strong as to block nearly all new construction in our powerhouse metropolises. Sure, theoretically, we could remake the cultural and ethnic mix of our communities with new arrivals of all colors and creeds. But the forces of nativism in America are already so strong as to barely tolerate the current level of multiculturalism. In his wonderful optimism about America, Yglesias forgets the deep sclerosis that has beset the country. Practically speaking, immigration could yield a few tens of millions more Americans, not One Billion Americans. That is very much worth doing, but it is not enough.

We need a different proposal. We need a proposal that can rise to the magnitude of the challenge, achieving massive growth rapidly, while also being practically possible. We need Canada and Mexico to join the Union.

This is not some “globalist” project; this is not an attempt to erect some supranational “North American Union” like the EU. The goal would not be to have Canadians, Mexicans, and Americans somehow coexist in a supercharged version of NAFTA. Rather, it would be to make Canadians and Mexicans Americans—to make them part of the political community. It would be an affirmation of the nation; a reinvigoration of the age-old project of the United States; a fulfillment of the American destiny.

Accepting Canada and Mexico into the Union would inject the nation with new lifeblood: young men and women eager to work hard, entrepreneurial minds with fresh ideas, and new industrial heartland to support a resurgence of domestic production. The enlargement of the Union would jolt innovation and economic growth, and the United States could once-again boast the world’s mightiest economy. With her newfound scale and increased economic independence, America could reclaim her military preeminence and defend her hegemony, rooting the world in the 21st century in liberty, prosperity, and peace as she did in the 20th.

Critically, the assimilation of new Americans is easier when it’s not happening in your backyard. To be sure, it would still be a stretch—both for Americans as well as for Canadians and Mexicans—to bind together in a common political community. But it would surely be easier than integrating hundreds of millions of foreigners in existing communities.

To be clear, some of the new Americans, i.e. former Mexicans and Canadians, would choose to move to the original 50 states. Some would move the other way as well. While somewhat disruptive, this is part of the point. We would want budding Mexican entrepreneurs move to Silicon Valley, Canadian auto-experts to move to Detroit, and American artists to move to Mexico City. But ultimately the scale of this would likely be limited, as the example of the EU demonstrates. Despite open borders between the European nations and substantial differences in the level of economic development, internal migration remains rather modest. We don’t see large fractions of the Greek population moving to Germany, for example, despite Greece’s ailing economy; family and cultural ties are too strong. What’s more, the newly-admitted states, particularly the Mexican ones, would experience an explosion of economic growth—so the vast majority of Mexicans and Canadians wouldn’t feel the need to move anyway.

As such, existing Americans could mostly continue to live their lives in their established, unchanged communities. What they would experience, however, is the renewed dynamism and prosperity that the nation would soon enjoy.

The Example of German Reunification

That such a nation-enlarging project is possible is demonstrated by German reunification in 1990. At first glance, German reunification would seem to be something entirely different than the proposal we are considering: not distinct countries, but one country, ruptured by the Cold War, reuniting at long last. But after 41 years of division, many—if not most—in both East and West Germany saw the other as a foreign country. East and West Germans were strangers to one another. And the differences between the two countries could have hardly be starker. One was a practiced democracy, the other had just held its first free election after decades of dictatorship; one had a thriving market economy, the other was socialist planned economy in shambles; one had a GDP per capita of roughly $19k, the other had a GDP per capita of roughly $5k (in 1990 PPP-adjusted dollars). In fact, it wasn’t even reunification in a technical sense. Rather, the former Eastern states acceded to the existing West German federal republic.

Although you’ll still hear the occasional grumbling (“xyz was better under socialism!”), East Germany’s accession to the West German federal republic has been a resounding success. The East German economy was dramatically modernized; the former East can now claim a GDP per capita of €32k, roughly 75% of the former West’s GDP per capita of €43k. Perhaps most importantly, there is clearly a united political community. While there is still a somewhat distinctive East German identity, East Germans primarily think of themselves as Germans. And all of this was achieved in a mere 30 years. The united Germany is now an economic powerhouse and a leader in Europe.

Canada’s GDP per capita is relatively similar to the U.S.’s, and Canadians speak English, so its 38 million people should be integrated into the Union with relative ease. The Mexican situation is perhaps more analogous to the East German one. In PPP-adjusted terms, Mexico has about a third of the GDP per capita of the U.S., and its 126 million population is a similar fraction of the U.S. population as the East German population was of West Germany’s population. The German example demonstrates not only that successful accession is possible, but economic convergence in a few decades is too.

Culturally, too, the combination of Canada and Mexico would fit in nicely in the United States. For America uniquely combines the European tradition with a Latin American streak—a commitment to hard work, religious faith, and a bit of creative chaos. The amalgam of Canadians and Mexicans would combine these traits. And although Mexicans don’t speak English, don’t discount the language ties with U.S. either. Over 10 percent of U.S. households speak Spanish at home, many communities in America are all but bilingual, and American political campaigns already run ads both in English and Spanish.

Perhaps my personal background colors me too optimistic about this project. I am product of German reunification. My mother grew up in East Germany, while my father grew up in West Germany; they met not long after East German accession. I thus firmly believe in the promise of once-foreigners uniting in a common political community. And I am a product of American’s capacity for assimilation. The two years I spent in America between the ages of 5 and 7, even though we returned to Germany afterwards, practically made me into a little American. I have confidence in America’s ability to mint new Americans.

Of course, it was an extraordinary political moment at the end of the Cold War that gave the impetus for German reunification. I do not harbor the same optimism that America will gather the political will to welcome Canada and Mexico into the Union—just that she could successfully integrate them if she so chose.

The Glory of American Institutions

The example of the European Union would seem to suggest that a continental union is doomed. The EU has failed to engender a common political community, while the schizophrenic combination of a currency union without fiscal integration has wreaked economic havoc in a series of crises in the last decade.

But America’s institutions are uniquely suited to accommodating a larger Union. America is already incredibly expansive, diverse, and heterogenous. She molds together Black and white and Hispanic, metropolises and hinterlands, California leftists and Mississippi conservatives, and a surprising gradient in the degree of economic development. Sure, the resulting national political debate may be caustic, and individual states go their own way on many issues—but on the essence of the political, on war and peace and the core values of liberty and democracy, the United States is a common political community.

It is perhaps exactly the contentious national political debate that binds the states into one. In Europe, there is never a continent-wide debate over the direction of the EU; there is no presidential election in which the voters get a clear choice and voice. Citizens are wholly disconnected from the EU as a political entity. But the bombastic spectacle of America’s presidential elections gives the citzenry the sense that they have a stake in the national body politic.

America also possesses a unique quality as the “shining city on a hill.” American ideals and the American story have extraordinary appeal beyond her existing borders. This would give her the power to inspire a sense of common purpose in a enlargened Union. In many ways, too, the world has become Americanized, with American culture and politics globally dominant. Canadians and Mexicans already live in an American world. In that sense, it wouldn’t be that big of a leap for them to fully become part of America—in fact, it may be simply formalizing how many already feel. America would have a unique ability—unparalleled by any other country—to forge a common political community with new entrants. America could succeed where the EU failed.

At same time, the United States has a robust system of federalism. Individual states have local control over many important policies. In a larger and more heterogenous Union, federalism would be central. Canadians and Mexicans would retain a healthy degree of self-determination; the Canadians would be free to keep their public health care at the state level, for instance. To the extent that an enlargement of the Union would encourage a return to more federalism and decentralization, that may well be healthy for American political life, defusing some of the bitterness and combat on the national stage.

Critically, the federal government does retain substantial fiscal levers in addition to control of monetary matters. This allows the United States to function as a coherent single economy—unlike the EU, which seems to more closely resemble the failed Articles of Confederation government which preceded the current U.S. federal system. America also has very capable federal law enforcement agencies. These could help root out the drug violence and corruption that have so plagued Mexico.

To be sure, a 500-million strong Union that spanned a continent and diverse cultures and economic circumstances would face a host of challenges. The accession may well strain American political institutions. But, ironically, the Trump era has demonstrated the astounding resilience of American democracy. America has shown she can effectively constrain an aspiring strongman and peacefully handle extreme political divisions. This bodes well for handling the tensions of larger Union. And although many complain about the dysfunction of American governance, this also means there is less to lose. If anything, admitting more states might reshuffle American politics and perhaps break some of the political gridlock.

Don’t forget, too, that America has done this many times before. New Yorkers had to accept the accession of Florida and Texas and California and Alaska. In 2008, America elected a President born in her most recent addition, Hawaii—in fact, he was born there just two years after Hawaii gained statehood. American expansion didn’t weaken the nation, but imbued the nation with energy and verve.

Why Canada and Mexico Would Want to Join

This essay has primarily considered why the U.S. would want Canada and Mexico to join. Of course, this could only happen voluntarily. Canada and Mexico would have to request admission to the Union. Why would they want to?

The case for Mexico is clearest. American investment and technology and institutional capacity would flow into the newly-admitted Mexican states, heralding unprecedented economic prosperity. Scores of Mexicans already brave the Rio Grande in search of American economic opportunity; joining the Union would obviate the need for desperate migration and instead allow that economic opportunity to come to them. If the newly admitted Mexican states experienced anything close to the economic convergence that East Germany achieved, it would lift tens of millions of Mexicans out of poverty.

The pitch to the Canadians is less obvious. Canada’s economic development is on a similar level as the existing United States. Of course, Canadians too would benefit tremendously from the larger common market of the U.S., but is that worth giving up political self-determination? Ultimately, however, Canadians would probably have a larger voice in their own affairs as part of the U.S. than they do as an independent nation. Canada is already part of an American world; American elections, for example, are likely more closely followed and more consequential for Canadians than their own elections. Joining the Union would give them a voice in matters of war and peace and world affairs—they would finally get a vote in the election that’s most important for them anyway. At the same time, American federalism would preserve much of their existing autonomy in domestic matters.

Conclusion

Fundamentally, I think a bigger America would be a better America. Canadian and Mexican accession would reinvigorate innovation and economic growth, sustain American hegemony, and be a historic humanitarian achievement. And I think the grand project of a larger Union would energize the nation with new hope, ambition, and vitality.

Of course, a dramatic project like this one would present a litany of thorny issues. Consider this essay an invitation to do the hard work of figuring those out—and an invitation to think bigger about the possibilities and potential of America. We need new ideas about our governance and our institutions. To the extent you may think this is a crazy idea, that’s because everything else has become so torpid.

Folks, decadence is a choice. Let’s make a different one.