The fight over the future of the U.S. military in Europe has faced powerful cross currents.
Advocates for the "Pacific pivot" were eager to shift resources to the other side of the globe.
As Congress pressured the Pentagon to cut costs across the board, budget hawks wanted to shutter more Cold War-era installations to save money.
But after Russia invaded Ukraine, diplomatic pressure from NATO allies and others sought to do the opposite and ramp up the American military presence in U.S. European Command to counter the renewed Soviet-style aggression.
The final decision: Not much will change. The Pentagon on Thursday unveiled the results of its two-year review of the U.S. military footprint in Europe, known as the European Consolidation Initiative, or ECI, and concluded there will be no major adjustment to the overall U.S. force level.
The new plan calls for shifting some troops within EUCOM. The biggest change will affect the Air Force in England. Two new F-35 Lightning II Joint Strike Fighter squadrons will deploy to RAF Lakenheath by 2020, along with about 1,200 airmen. And the Air Force will close nearby RAF Mildenhall, now home to about 3,900 personnel, in 2019.
The Air Force units from Mildenhall will move to Germany. Specifically, the KC-135 Stratotankers will transfer to Ramstein Air Base and the 352nd Special Operations Wing will move to Spangdahlem Air Base.
Meanwhile, the Army's footprint in Europe, and remaining Cold War-era military bases in Germany and Italy, will be mostly unaffected by force structure changes. The size of EUCOM's permanent American force will stay at about 67,000 for the next five years, officials said.
That garrison force will be buttressed by additional "temporary" U.S. troops, as the Pentagon renews its commitment to the rotational deployment of hundreds of U.S. service members to Eastern Europe.
Those rotations, involving mostly soldiers and airmen spread in small units across Poland and the Baltic states, began last year to reassure NATO allies growing anxious about Russian military aggression.
"The intent is to continue this rotational presence into the future," said Derek Chollet, assistant secretary of defense for international security affairs, at a Pentagon briefing Thursday.
"As things change in Europe, things get better or perhaps things get worse, we may adjust accordingly," Chollet said.
EUCOM initially filled those rotations with its own forces assigned to Western Europe, but is requesting U.S.-based Army and Air Force units to provide additional support.
Costs for the rotational forces and some new infrastructure investments in Eastern Europe will be covered by the $1 billion "European Reassurance Initiative" that Congress approved last year. The ERI is intended to bolster the 2015 budget and was specifically intended to address NATO concerns about Russian aggression. Its long-term funding is unclear.
The EIC review also included more than 20 closures of small, under-used military facilities across Europe. For example, the American-run Amelia Earhart Hotel in Wiesbaden, Germany, will close and the Vicenza Health Center in Italy will be converted into an outpatient-only facility.
A total of 15 properties, including Mildenhall, will be returned to host nations.
Overall, the changes will save the Pentagon about $500 million a year, a small fraction of the total defense budget of more than $500 billion, officials said.
Pentagon officials emphasized that the changes will not affect the military's overall war-fighting capacity in Europe.
"We are consolidating and reducing some existing support infrastructure in order to be more efficient, but we are not affecting our operational capability," Chollet said, adding that the changes "do not diminish our ability to meet our commitments to allies and partners. In fact, these decisions will produce savings that will enable us to maintain a robust force presence in Europe."
The top U.S. commander in Europe, Air Force Gen. Philip Breedlove, voiced support for the changes. "The adjustments and resulting efficiencies will help ensure the U.S. can maintain a persistent and capable presence in Europe," he said in a statement.
Last year, the mounting tension with Russia prompted top U.S. officials to reassess the ECI effort, which began in 2013 as a cost-cutting project.
Russia's seizure of the Crimean Peninsula in February and incursions into other parts of Ukraine last year sent shock waves across Europe, especially among the former Soviet satellite states that are NATO's newest allies in Eastern Europe.
That led the U.S. military to deploy several units eastward, including company-sized Army units to Poland, Latvia, Lithuania and Estonia as well as several Air Force fighter jet and cargo plane detachments into Poland.
Poland publicly urged the U.S. to consider setting up a permanent garrison base there.
Russian aggression reached further west this fall when unusually large formations of Russian military aircraft made incursions into NATO airspace over the United Kingdom and Portugal. In 2014, NATO aircraft conducted more than 100 intercepts of Russian aircraft, a threefold increase over the year before.
In September, Defense Secretary Chuck Hagel wrote a private letter to the White House, urging a more aggressive stance toward Russian President Vladimir Putin and expanded measures to reassure European allies, according to a report in the Wall Street Journal.
As new and fast-moving strategic concerns began to weigh on the ECI, top officials considered halting the review.
"Obviously, when events occurred in the Ukraine, we took a look and asked the question to ourselves, you know, 'Should we pause this?' " said John Conger, acting assistant secretary of defense for energy, installations and environment.
"We decided to continue with the analysis, because ... the question that we're asking ourselves is, how can we do the same thing for less money? That question's still pertinent," Conger said.
Retired Adm. James Stavridis, a former NATO supreme allied commander, said tension with Russia derailed the post-Cold War drawdown of U.S. troops and plans to reallocate those resources elsewhere.
Keeping force levels flat in Europe will limit the Pentagon's plan to "rebalance" or "pivot" the military's focus toward Asia.
"I think there is a growing realization that the 'Pacific pivot,' while a good idea theoretically, has collided with the reality of bad Russian behavior in Europe. And we have discovered that we have serious security issues to face with our NATO allies in Europe," Stavridis said in an interview Thursday.
"Three years ago, when the 'Pacific pivot' was announced, I would have expected U.S. force levels in Europe to be lower than they are now. But because of the events in Ukraine, I think we are seeing a halt to that decline," said Stavridis, who is now dean at Tufts University's The Fletcher School of Law and Diplomacy.
The Pentagon is leaving enough infrastructure — buildings, airstrips, training ranges — to allow for a significant increase in troop levels in the future if conditions warrant, Stavridis said.
Individually, some services have begun stepping up capabilities in Europe. The Army plans to send a brigade of tanks and Bradley fighting vehicles back to Europe, reversing a drawdown of heavy armor that occurred several years ago.
The Navy is pressing ahead with plans to permanently dock four Arleigh Burke-class guided-missile destroyers in the Spanish port of Rota.
The ECI review did not specifically address questions about the future of the 21 F-15 fighters that are based at Lakenheath.
Last year, the Defense Department's official budget proposal for 2015 — compiled before the Russian invasion of Crimea — sought to remove those aircraft from Europe. But that will not happen immediately; the fighter jets got a one-year extension in Europe as part of the funding for the European Reassurance Initiative.
"All of that is being relooked," said one defense official.
Other changes to EUCOM will include significant reductions to military personnel and operations at Portugal's Lajes Field, used by U.S. aircraft since World War II. The airfield, on an island about 850 miles off the Atlantic coast of Portugal, was once a refueling stopover for transatlantic flights.
Defense officials say the personnel, including about 650 service members and civilians as well as contractors, will be cut by about two-thirds and DoD will turn over several buildings to Portugal.
Europe was an inviting target for budget cuts because the Pentagon has the authority to close bases there without an act of Congress.
To close bases at home, DoD must get explicit congressional approval. Closures are controversial due to the local economic impact and usually require an elaborate legal process known as a base realignment and closure commission, or BRAC.
The Pentagon repeatedly has asked Congress to convene a new BRAC to help shave money from the military budget by reducing excess overhead costs. Congress has repeatedly refused, inadvertently putting pressure on overseas bases.
The EIC officially lays out the Pentagon's plan for EUCOM through 2020 and beyond. But given Russia's unpredictability and the changes elsewhere in the world, this plan probably has a "three-year shelf life," Stavridis said.
"The next phase of this will be to continue to watch Russian behavior and decide whether we want to add forces back into the mix," Stavridis said.