(AP Photo/Ross D. Franklin, file)

Since Donald Trump issued his campaign position paper saying that, as president, he would deport all the undocumented immigrants living in the United States, many have argued that deporting 11.4 million people would have serious economic and humanitarian repercussions. Pulling long-rooted family systems apart would be socially destabilizing. Removing a significant share of low-income labor would radically transform how we buy and sell things.

Trump and others who support mass deportation tend to ignore these criticisms and change the topic to national security. But immigration and national security are related in ways rarely discussed. How would such forced deportation affect the U.S. government’s ability to grow its economy, increase military spending, and maintain military power and international standing?

Right now, the U.S. population is roughly 325 million, with an average fertility rate of 1.9 per woman. According to the International Futures (IFs) modeling platform–a computer simulation of global development used to inform strategic decision-making—if today’s trends continue, the U.S. population would increase by 31 million people over the next 15 years.

If this comes to pass, the U.S. economy would expand at an average annual rate just north of 2 percent. In other words, the real value of what is produced by the U.S. would increase from $17 trillion today to $22 trillion in 15 years. Assuming that military spending as a share of GDP declines from 4 percent of GDP today to around 3.7 percent of GDP by 2025, military outlays would also increase, from $720 billion today to more than $880 billion in 2030 (adjusted for inflation).

Let’s assume that all associated growth would continue apace as well: including development of technology, extended diplomatic reach, and other factors usually used to measure national capabilities. Even so, growth in the U.S. would not be keeping pace with growth in China. According to a new index used by the National Intelligence Council, the U.S. currently has 20.7 percent of the world’s material and institutional capabilities–global power, in ordinary terms—while China has 15.5 percent. By 2030, according to the same forecasts, this would have flipped. China would possess 19.5 percent of global capabilities and the U.S. would be left with 16.8 percent.

But mass deportation would change that forecast dramatically. If the U.S. were to get rid of 11.4 million people, fertility rates would drop proportionally (especially considering that immigrants tend to have larger families). And the relative capabilities of the United States would be depleted that much more rapidly. By 2017 the U.S. economy would be nearly $400 billion smaller than otherwise expected. By 2030 that shortfall would increase to more than $1.5 trillion. If you add up the next 15 years of losses, by 2030, U.S. economic output would have shrunk by more than $12 trillion. (The impact on GDP per capita would be relatively small, changing within a 1 percent band.)

In just two years, if military spending as a share of GDP remained constant, the money available for the U.S. military would decrease by more than $20 billion. In 2030, the U.S. military would have nearly $70 billion less than it would with a U.S. full of immigrants.

Overall, a U.S. that deported all its undocumented immigrants would reduce its military spending cumulatively by more than $500 billion over 15 years. What’s more, fewer people, less economic output, and reduced military spending would mean a less powerful U.S. If the U.S. deported all its undocumented immigrants, by 2030 it would have only 15.8 percent of global power, not 16.8 percent. That one percent may not sound like much – but it’s the equivalent of all of Australia’s current share of global capabilities.

And that’s looking only at how much deportation would reduce U.S.’s global share of power. There’s much more. The U.S. would find it much harder to pay Social Security, Medicare, Medicaid, and all other social services. Fewer working people would be supporting the same number of retired, elderly, and disabled people. The U.S. would look less robust and more like today’s Europe and Japan.

Of course, mass deportation would have one silver lining: by 2030 U.S. annual carbon emissions would be five percent lower than without deportation, reducing the U.S. contribution to climate change. But, of course, those forced to leave the U.S. would just be emitting carbon elsewhere (though possibly not as much).

In sum, removing 5 percent of the U.S. labor force would reduce economic output, constrain military spending, and increase the relative power of China. Calling for both deportation and a strong U.S. military presence abroad is logically inconsistent.

Jonathan D. Moyer, Ph.D., is Research Assistant Professor at the University of Denver Josef Korbel School of International Studies and Acting Director of the Frederick S. Pardee Center for International Futures.