The Pentagon is preparing to present Defense Secretary Pete Hegseth no fewer than four different options for reducing the size of what it calls its "military posture" in Europe within the next few weeks before the review deadline in December, weeks ahead of schedule, according to a six-month audit of the U.S. military presence in Europe led by President Barack Obama. The mechanics are described in a document reviewed by Reuters for the first time, and what it shows is a process that has been designed intentionally to maintain a wide range of options, such as the possibility of a drawdown of American troops about 80,000 forces are deployed on the continent right now and the possibility of a marked drawdown.

The timeline is an indicator of urgency. Under Secretary of War for Policy Elbridge Colby will take NATO ambassadors on a dolly through the terms of reference of the review in Brussels, at the alliance's headquarters, officials on both sides say a key factor in determining what ends up on Hegseth's desk. The conduct of the exercise was meant to be "very open," a senior Pentagon official, who asked not to be named, said. The idea was to consider all levels of force not to pick a winner. The same official admitted that there's an obvious demand signal in the building for something that would reflect reduced American presence, but insisted there was no attempt to preordain the outcome of the review.

It's this uncertainty that is troubling capitals of Europe. The review begins in June, when Hegseth was in Brussels and announced the end of the free-rider era among several NATO allies who depend on U.S. strength, but fail to invest in NATO's capabilities. He designed the upcoming reassessment as an implementation of what Colby has been dubbing NATO 3.0, a strategy in which European countries will shoulder the main burden of defending their own continent, while Washington looks toward the Western Hemisphere and the Indo Pacific. The announcement came as Europe was clearly in the role of mediator in the recent US-Israeli confrontation with Iran, and as the United States was becoming increasingly impatient with European hesitation in this regard.The announcement coincided with growing American impatience with Europe's hesitation as it played a mediation role in the US-Israeli confrontation with Iran recently, as well as with its continued sense that the division of labor within the alliance had become unequal and unsustainable.

Colby has been the mastermind behind this change, and he has been public about the thinking in his recent speeches over the past few months. He has contended that NATO's founding generation, from Eisenhower to Adenauer, did not plan to keep Europe permanently as a military protectorate of the United States, and that NATO had an original purpose as a military partnership between its members, not as a military arms race with the Soviet Union. The administration has also cited the economics behind that argument: NATO's European partners and Canada account for a combined economic output valued in the tens of trillions of dollars, much greater than Russia's entire economy, and are more than capable of funding their own conventional deterrent if they so choose and then shift some of their wealth into that realm.

Movement has already taken place on the spending side of the ledger. At the Hague meeting last year, the alliance members pledged to meet a new target of 5 per cent of GDP in defence expenditure, with 3.5 per cent allocated to the core military force and the remainder, 1.5 per cent, to infrastructure to move forces around the continent from ports to rail lines to airfields. NATO's secretary general has stated that there is now widespread support for that objective and that the members are making fast progress towards it ahead of the summit of NATO leaders. For several years in a row, Poland has been ahead of its neighbors on this metric, having tipped the 4 percent mark well before most of the alliance began taking its budget seriously, and it is something of an unofficial blueprint for what Washington hopes the rest of the alliance can do.

But the numbers of committed spending and the numbers of committed troops are not the same thing – and that is what is causing the diplomats in Brussels to truly feel anxious. There are unequal concentrations of American troops throughout the country. By a wide margin Germany remains the home of the largest single force, with most of it remaining as a result of the Cold War basing arrangements which have not been completely phased out by successive German governments who have reduced the numbers of troops stationed there. Since 2022, the alliance has pulled back towards its eastern flank and has seen Poland and the Baltic states expand their rotational presence, while Italy and Britain continue to have significant numbers of their troops stationed on the bases related to navy, air and logistics operations, not to frontline defense. All four possible scenarios for Hegseth would have a lopsided effect on that map and each host country is quietly lobbying in Brussels this week to not bear the brunt of the worst economy.

There's a growing argument, now increasingly openly voiced within the Pentagon, which this rebalancing is not "retreat," but a rebalancing long overdue and over 30 years past due. But through that lens, a force posture designed for a Europe that was incapable of or unwilling to defend itself no longer aligns with a Europe whose economies have grown larger than Russia's and whose governments, for the first time, have finally come to an agreement on paper, to pay for it. But critics on Capitol Hill and in European foreign ministries argue that intentions on the spreadsheet take years to manifest themselves on the ground in brigades, air-defense batteries and munitions stockpiles and that pulling out U.S. troops before European replacements can be fielded can create exactly the space that Moscow desires.