An emerging but familiar threat has become the "greatest focus" of the Army's No. 2 general.

In light of that threat — on top of several other demands for U.S. soldiers around the world and a tight fiscal environment — the Army must make sure it can continue to assure its allies, fulfill its NATO responsibilities, and "continue to rotate trained and ready forces" to support the deterrent work led by U.S. European Command, Allyn said.

Allyn spoke June 25 to Army Times as Defense Secretary Ash Carter met with Ukraine's defense minister, Colonel-General Stepan Poltorak at the NATO Defense Ministerial in Brussels.

The two leaders in Brussels discussed Russia's ongoing aggression in eastern Ukraine, according to information released by the Defense Department. Carter emphasized the United States' commitment to support Ukraine "in its effort to define its own course as a sovereign, democratic nation," according to DoD.

Carter also reaffirmed U.S. commitment to continuing defense cooperation with Ukraine, including through exercises and training.

A US soldier, right, instructs Ukrainian soldiers during joint training exercises on the military base in the Lviv region, western Ukraine, Wednesday, June 3, 2015. Troops from the United States and Ukraine conduct joint training exercises intended to help bolster Ukraine's defense against incursions from Russian-backed separatists. (AP Photo/Andrew Kravchenko, Pool)
A US soldier, right, instructs Ukrainian soldiers during joint training exercises on the military base in the Lviv region, western Ukraine, Wednesday, June 3, 2015. Troops from the United States and Ukraine conduct joint training exercises intended to help bolster Ukraine's defense against incursions from Russian-backed separatists. (AP Photo/Andrew Kravchenko, Pool)

A U.S. soldier instructs Ukrainian soldiers during joint training exercises on the military base in the Lviv region, western Ukraine, on June 3.

Photo Credit: Andrew Kravchenko/AP

Operation Atlantic Resolve has since expanded, including into Romania and Bulgaria, with the Army sending a brigade combat team, aviation task force and division headquarters into the region to support the ongoing exercises.

These rotational forces "continue to deliver vital capabilities to enable our combatant commanders to deter threats, shape their security environment and strengthen their resolve," Allyn said.

The Army also is beefing up its equipment set in Europe — growing from a battalion's worth of tanks and Bradley Fighting Vehicles to a full brigade complement.

Budget cuts and the drawdown

On top of the tensions in Europe, the Army is deployed around the world, including in Afghanistan and Iraq. It also is preparing to cut an additional 40,000 soldiers from its ranks as it faces increasingly tight budgets.

"We remain in a very tough resource environment," Allyn said. "Our budget for this year, in 2015, was $5 billion less than last year. We are absolutely dependent upon the timely passage of the president's budget for 2016 to enable us to continue to build momentum in training and readiness, and to ensure we can deliver trained, ready and properly equipped forces to meet the emergent demands across this unstable world."

By the end of this fiscal year, the Army will have cut 80,000 soldiers from its active-duty force. It will further reduce its end-strength to 450,000.

"Given the depth of the cuts we've already taken, some people would say, 'what's another 40,000?'" Allyn said. "The challenge is we've taken all of the slack out of the rope."

To get to 450,000, the Army will make "some very tough choices that will have very broad and deep implications for the Army and the country," Allyn said.

The Army has reduced the troops stationed overseas "to the maximum that we could already, so the cuts are going to come largely from within the continental United States, and they are going to be very, very impactful," he said.

In the coming weeks, Army Secretary John McHugh is expected to make a final decision about where those cuts will occur.

Army leaders continue to hope Congress will pass the president's budget, Allyn said.

"Then we'll exert the leadership necessary to eliminate sequestration as a continuing threat to our national security so that we can stop the bleeding at 450,000," he said.

To keep up with the cuts, the Army is racing to build the readiness of its brigade combat teams.

"The chief of staff made the decision a couple years ago that we would build the Army contingency force because of the magnitude of global instability," Allyn said. "We knew we had to be able to provide land forces for one of those emergent flashpoints."

Right now, the Army has the capability to provide forces if needed to respond to a contingency, Allyn said.

In January, the Army deployed paratroopers from the 82nd Airborne Division's 3rd Brigade Combat Team to Iraq to support the advise and assist mission there.

"As we've answered emerging requirements like the plus-up in Operation Inherent Resolve several months back … that came out of our Army contingency force," Allyn said. "We're consuming readiness as fast as we're generating it because of the demands that are out there."

The ongoing challenge – the Army wants up to 70 percent of its brigade combat teams trained and ready if needed; it is only at about 30 percent now – is funding, Allyn said.

"The challenge is if we don't receive predictable funding … we will not be able to train the follow-on forces to the level that they should be trained," he said. "We will continue to focus on our contingency forces as our top priority, but we require predictable funding for home station training for all Army forces. We don't want to get into a tiered readiness scenario."

Also affected is the amount of time soldiers have at home in between deployments.

"As we get smaller and the demands stay stable or grow as they have been over the last couple of years, that means fewer forces are deploying more frequently," Allyn said.

The Army has yet to achieve its goal of a 1-to-2 deployed to dwell ratio, Allyn said.

Ideally, if a soldier is deployed for a year, he should get two years at home.

"It does not appear, based on the demand signals we're seeing going into 2016, that we will make much progress on that," he said.

The good news for soldiers, he said, is they are given the opportunity to have an impact around the world.

"It's an exciting time to be serving in the United States Army," he said.

Allyn recounted meeting a staff sergeant in the 1st Cavalry Division who briefed the two-star senior logistician for the Lithuanian army on how to build a unit maintenance program.

"It was supposed to be a 30-minute brief. It went for four hours, and then this major general came back to this staff sergeant two additional times," he said. "That's the impact that our leaders in the United States Army are having. They are empowered, they are delivering vital mission support around the globe, and they see the effects of what they're doing."