The economic argument for keeping US forces in Europe

NATO’s Hague summit earlier this summer has generally been viewed as a qualified success, despite — or perhaps because of — its unusually short and focused agenda. The new 5 percent defense spending commitment deserves most of the credit for this perception, but there’s no escaping the conclusion that the lack of major disruptions also explains why most alliance watchers viewed the summit as a win.

Nonetheless, Europeans — and even some Americans — remain concerned about the durability and strength of the US commitment to European security. Maintaining that commitment, especially through its most obvious manifestation — the presence of a robust array of US forces in Europe — won’t just help Europeans transition to a point where they have the capabilities and capacity to truly stand on their own. It can also help ensure US vital interests in a secure and stable Europe.

Doing otherwise risks placing the US-European trade and investment relationship — the largest in the world — in jeopardy, threatening millions of American jobs and potentially undermining the American way of life. The first Trump administration argued “economic security is national security.” When it comes to basing US military forces in Europe, the reverse is also true: National security is economic security.

Despite recent public assurances by American officials, Europeans remain concerned about the US commitment due to a litany of comments from the White House. For example, ruminating on seizing Greenland, characterizing the EU as designed to ruin the United States, accusing Denmark of mishandling security in the Arctic, and declaring that Canada should become the 51st state make the US look more like an antagonist than an ally, at least in European eyes. At the same time, the US has taken a far more engaging approach toward Russia in recent months, despite ongoing atrocities committed against Ukrainian military forces and civilians and an intensifying hybrid war waged by Russia across the continent. Additionally, US officials have indicated a likely drawdown of conventional forces in Europe at a time when allies are least prepared to backfill American capabilities, given European efforts to supply Ukrainian forces. Finally, many expect the next US national security strategy to heavily prioritize the challenge of China and specifically a Taiwan-focused scenario, at the expense of threats and concerns elsewhere.

There are similar concerns among Americans officials outside the administration regarding the durability and strength of the American commitment to European security. When reports emerged that the United States might not nominate a four-star officer to replace retiring US Army General Christopher Cavoli, NATO’s most senior military commander, Republican leaders of the Senate and House Armed Services Committees took the unusual step of voicing their concerns publicly. Some members of the Senate Armed Services Committee also expressed their opposition to reducing the US military presence in Europe. (Those reports ended up not coming to fruition.)

Despite these objections, it seems highly likely that the United States is going to significantly reduce its role when it comes to deterrence and defense in Europe. At best — from a European security perspective — American extended nuclear deterrence will remain, but whether this commitment is robust enough to actually deter the Russians in the absence of a strong conventional American force presence in Europe remains unclear, especially if Article 5 is conditioned in any way.

For this reason, significantly downsizing the US conventional posture in Europe, giving up key American leadership positions in NATO’s command structure, or backing away from the alliance in other ways would be exceptionally perilous. Such risky moves would likely increase Russian aggression across Europe, not decrease it, even if Washington maintains its extended nuclear deterrent.

But this isn’t just about US defense interests. Remember, capital flees instability and insecurity, meaning the second-to-none US-European trade and investment relationship could be in jeopardy if war expands on the continent.

Helpfully, we can look to history for evidence of how an adversary reacted to an American drawdown in overseas force posture. In February 1949, the CIA assessed the impact of an unfolding drawdown of US military forces from South Korea that had started the year prior. That analysis concluded that the drawdown would probably be followed by a North Korean invasion. Nonetheless, nearly all 40,000 US troops were withdrawn from South Korea between 1948 and June 1949, with the exception of a small advisory and training contingent of about 500 troops. Predictably, at least from the CIA’s perspective, the North Korean army invaded South Korea a year later in June 1950.

The resulting Korean War led to the deaths of over 33,000 American servicemembers and cost the US Treasury the equivalent of $370-400 billion in inflation-adjusted terms. It’s impossible to know whether maintaining a more significant presence in South Korea would have deterred an invasion by the North in 1950 or thereafter. What is clear though is that the cost of maintaining 40,000 troops in South Korea would have been less than the price paid — in blood and treasure — to eject North Korean forces.

If Russian aggression against Europe increases in the aftermath of an American pullback from leadership within NATO or from the US military presence in Europe that underwrites that leadership, the likely result is going to be a far costlier effort to eject Russian forces. Why would the United States participate in such an effort today? For the same reason it sent its sons and daughters to fight in and defend European allies three times in the 20th century — because our economic interests would require it.

Moreover, even in a world absent the catastrophe of a Russian invasion of a NATO ally, a hasty, dramatic drawdown of America’s role in Europe will make it less likely European allies would assist American efforts in any Indo-Pacific contingency. Europeans sitting on the sidelines of such a conflict would represent a stark contrast with their strong participation in US-led interventions in Iraq and Afghanistan. In both conflicts, Europeans provided roughly one-third of all troops on the ground, deploying to both conflicts year after year and sustaining casualties at higher rates than the United States in some cases.

The best way to protect vital US economic interests in Europe and ensure European allies will answer Washington’s call for assistance in the event of an Indo-Pacific crisis is to maintain American leadership within NATO and a robust US commitment to European security and stability.

John R. Deni is a research professor at the US Army War College’s Strategic Studies Institute, a nonresident senior fellow at the Atlantic Council, and a nonresident senior fellow at the NATO Defense College. The views expressed are his own.