The Trump administration has only just begun to fill its ranks with the political appointees who will flesh out the future of U.S. defense policy. One item sure to be on their agenda is a review of U.S. military deployments around the world, known in Pentagon-speak as a posture review. As part of this process, officials are likely to scrutinize the status of U.S. military forces in Europe.

U.S. President Donald Trump’s first-term policies—and early rhetoric during his second term—indicate that the U.S. military presence in Europe is likely to change fundamentally as a result of the posture review. Over the last 80 years, the United States has played a leading role in conventional defense and deterrence in Europe. But the Trump administration has made clear that Europeans should take on primary responsibility for defending the continent.

There are several plausible reasons for this policy shift. First, the U.S. Defense Department is not immune to the cost-cutting measures unfolding across the federal government. There is a growing sense among some U.S. officials that the United States simply cannot afford to maintain its commitments in Europe if it is to focus on the threat posed by China.

A second possible explanation is that the Trump administration hopes that a reduced U.S. commitment to Europe will form part of a broader reset in relations with Russia. Recent interactions between senior U.S. and Russian officials—including a lengthy phone call between Trump and Russian President Vladimir Putin—indicate that the White House hopes to dramatically warm ties with the Kremlin.

Ultimately, a closer U.S.-Russia relationship might encourage Moscow to loosen its ties to Beijing—although many experts are skeptical of this logic.

Finally, the Trump administration clearly views the European Union as an adversary—and the NATO alliance as resulting in an unfair European and Canadian dependency on the United States. As U.S. Vice President J.D. Vance said at the Munich Security Conference in February, “our European friends must play a bigger role in the future of this continent.” Observers might perceive cuts to U.S. forces in Europe as righting this imbalance.

With these potential rationales in hand, there are several means by which the White House might approach reducing the U.S. military footprint in Europe. If history is any indicator, a large-scale, hasty drawdown of U.S. forces in Europe could have disastrous implications for European and U.S. security—especially given Moscow’s aggressive, revanchist tendencies. But there may be ways for the Pentagon to rebalance its approach in Europe without sacrificing U.S. interests.

If the underlying logic behind the Pentagon’s posture review is to shift resources to deal with the most probable conflict with China—over Taiwan—a sensible approach would be to assess which U.S. capabilities currently based in Europe would be most useful in the Indo-Pacific theater.

These might include sea- and land-based air defense assets, such as Aegis destroyers based in Spain or Patriot air defense units in Germany. They might include anti-submarine aircraft, such as P-8 Poseidons stationed in Italy, as well as F-35 advanced fighter jets, B-1 bombers, and KC-135 refuelers in the United Kingdom. Finally, they might include strategic air lift assets such as C-130s held in Germany.

To be clear, relocating these capabilities to deter a possible future conflict in the Indo-Pacific while a massive war is still unfolding on NATO’s border is a high-risk strategy. However, the risk could be mitigated by leaving most U.S. land forces based in Europe unaffected by such a transfer, including field artillery, mechanized infantry, attack helicopters, paratroopers, and armored forces. They are less likely to be necessary in a Taiwan-centered conflict, and leaving these assets in Europe would enable the United States to deter and contain Russian aggression.

However, if factors other than a pivot to China are driving the Pentagon’s posture review, its drawdown of U.S. forces could be far broader, affecting all U.S. capabilities in Europe and carrying more significant implications for global security.

The U.S. military presence in Europe underpins the United States’ vital interest in a stable European continent. Hasty, large-scale reductions to this presence would unnerve U.S. allies and send the wrong signal to Russia, rewarding it for invading and intimidating its neighbors, violating international laws and norms, and committing wartime atrocities in Ukraine.

Such drawdowns would also send a bad message to China: Beijing would likely perceive them as an indicator of U.S. decline and of Washington’s questionable commitment to its allies and friends, such as Taipei.

From a practical perspective, a large-scale reduction in the U.S. military presence in Europe could immediately run into hurdles. Reducing the forward-based U.S. presence in Europe cannot occur overnight, as turning over U.S. military facilities to host countries such as Germany, Italy, or Romania would take years of negotiations.

Sending troops back home also requires that facilities in the United States be ready to receive them, and it takes time to build, expand, or modernize barracks and bases. Troops based in Europe include dependents, too. It’s unacceptable to ask military families to uproot their spouses and children in the middle of a school year.

A reduction in U.S. forces based permanently in Europe can’t happen instantly. But because administration officials may want more immediate results, it is likely that they would pursue quick wins where possible.

The most obvious option is to reduce the number of rotationally deployed U.S. forces on the continent—troops who are sent to Europe for nine-month rotations without family members. Since Russia’s 2014 invasion of Ukraine, the United States has sent thousands of U.S. troops to Europe on a rotational basis, primarily to Estonia, Latvia, Lithuania, Poland, Romania, and Bulgaria, which are the countries most exposed to Russian intimidation. Ending those rotations could happen quickly, possibly within weeks, if Trump ordered the Pentagon to do so.

Even if rotational U.S. forces are subject to immediate withdrawal, it is possible that a special exception might be made for Poland. Because of Poland’s precarious security situation and its history of subjugation to Russia, leaders in Warsaw have spent billions of dollars to build military facilities to host U.S. forces. Poland has also agreed to provide much of the fuel, electricity, water, and heating necessary to sustain those U.S. forces, who number around 10,000.

However, even if some U.S. troops were to remain in Poland, a large-scale reduction in the rotational U.S. presence within the other most exposed allied countries would deliver a body blow to European security—and U.S. security, too.

Europe is the United States’ most important economic partner. Roughly one-quarter of all U.S. trade is with Europe—more than with Canada, China, or Mexico. Over 2.4 million U.S. jobs are directly tied to trade and investment with the EU and the United Kingdom, versus just over 930,000 with China. Europeans also hold twice as much U.S. debt as China.

Simply put: U.S. and European prosperity are linked, and stability in Europe is vital to the American way of life. If Washington reduces the U.S. military footprint in Europe, it would be wise to tailor the reduction to specific geopolitical aims rather than executing a hasty, dramatic drawdown in forces. That is the more prudent way of meeting the needs of U.S. military commanders in the Indo-Pacific while safeguarding the vital trans-Atlantic alliance.