WASHINGTON — For years, the US administration has cast a longing gaze on a pivot to the Asia Pacific but wars in the Middle East have managed to divert attention.

And now Russia has re-emerged as the number one threat to the US. So if there’s a pivot happening anywhere it’s to Europe, and it’s clear the Army will lead.

President Obama's last budget request more than quadrupled the amount of overseas contingency operations (OCO) money funneled into what is being called the European Reassurance Initiative (ERI).

The $3.4 billion in fiscal 2017 funding is part of an effort to deter Russia's military aggression in Eastern Europe and to bolster allies' defense capabilities.

And it's clear that the majority of those dollars — $2.8 billion of it — are Army green.

The majority of the Army's OCO boost in the budget is due to ERI, Maj. Gen. Thomas Horlander, the Army's budget director, said.

Prior to 2014, before Russia annexed Crimea and invaded Ukraine, it would have been hard to imagine seeing a renewed Cold War-like posture in Europe.

"I never thought I'd see a land war in Europe again but when I went to Ukraine you saw it," Maj. Gen. Walter Piatt, director of operations, readiness and mobilization in the Army G-3, said.

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Army personnel has declined in Europe from roughly 200,000 during the 1980s to around 33,000 in 2015, according to a Center for Strategic and International Studies report, released this month, evaluating future Army force posture in Europe. The US had two Army Corps with heavy armored forces during the Cold War.

Now the Army has only two permanently stationed brigade combat teams, has closed over 100 sites since 2006 and is now concentrated in Italy and Germany, not near NATO's eastern flank, the report notes.

A defense official speaking to Defense News prior to the budget release recalled iconic photos of tanks coming out of Europe and noted now there would soon be photos of tanks coming back in.

Retired Adm. James Stavridis, who served both as the commander of NATO and US European Command, painted a picture of the European dilemma during a recent House Armed Services Committee hearing.

The Russians are conducting military operations with "cleverness," he said. "Some have called this hybrid warfare. It's a mix of special forces; information warfare; cyber ... and this element of surprise, building real ambiguity into their maneuvers."

But what is even more worrying, Evelyn Farkas, former deputy assistant secretary of defense for Russia, Ukraine and Eurasia, said, is Russian military doctrine that permits the country to respond to a conventional attack with nuclear weapons — from an arsenal that has already outpaced the US' aging one.

Part of the solution is to ramp up the US military's presence in Europe to delicately deter Russia's aggression in countries along its border.

That is where the US Army comes in. In fiscal 2017, $727 million will go toward "increased presence."

It’s not just about parading tanks around the streets of European towns; $50 million will fund building "partner capacity." A total of $89 million will expand the scope of 28 joint and multinational exercises annually.

The biggest chunk of funding — $2 billion — is for putting a "heel-to-toe" armored brigade combat team (ABCT) in theater 24/7 on a rotational basis on top of the Stryker brigade and infantry brigade already in Europe. The funding will also cover more aviation in theater.

A total of $1.8 billion of the ERI funding will pay for prepositioned equipment to include an entire ABCT static set of equipment, Horlander said, as well as some other enablers.

The Army has already established an "activity set" — separate sets of equipment outside of prepositioned stocks — that builds out a brigade combat team.

The countries that will see continuous rotations are, thus far, Bulgaria, Romania, Poland and the Baltics, a senior defense official said in Brussels.

However, prepositioned stock will likely be stored in facilities in countries like Germany because the infrastructure, dating back to the Cold War, is already there.

The Army is looking at rotations beginning on Oct. 1. Another unit will arrive in April 2017. The service is still identifying what unit will deploy first, a senior military official in Brussels added.

Army officials are still working out which ABCT might go to Europe and whether rotations will be nine months or shorter, Piatt said.

The service is also speeding up its plans to increase the lethality of its Stryker armored personnel carriers, an urgent requirement coming straight out of Europe.

The $2.8 billion in ERI is just the beginning, a defense official said. "What you are seeing is just a down-payment for the US commitment to securing Europe and getting back in."

More is bound to come in fiscal 2018 to bolster the Army's European presence.

For example, the official said, while not in the fiscal 2017 budget, the Armored Multi-Purpose Vehicle that BAE Systems is building for the Army could see procurement accelerate in the fiscal 2018 budget through OCO dollars in order to get more modernized equipment to Europe.

But since AMPV is still in the development phase, the official added, that remains a future decision.

The Army will also work to enhance interoperability among allies, being able to talk and share information on the move, according to Piatt.

Another gap in capability, Farkas observed, is the lack of intelligence, surveillance and reconnaissance. "We need more ISR for the US European Command."

In future years, the Army may choose to follow recent recommendations from experts as well.

The National Commission on the Future of the Army called for a forward-stationed ABCT rather than a rotational one.

And the CSIS report commissioned by US Army Europe recommends an additional activity set to go along with a second rotational ABCT, prepositioned stocks for four brigades, adding 1,000 personnel to headquarters and new logistics capabilities.

The report also recommends increasing cyber, integrated air and missile defense, electronic warfare, short-range air defense and communications capabilities in Europe.