(CNN) -- Whether viewed as a show of force to Russia or a sign of reassurance to nervous allies, the recent deployment of U.S. Army forces to Poland and three Baltic states is steeped in matters strategic and diplomatic to American foreign policy.
A contingent of 150 paratroopers arrived in Poland on Wednesday from their base in Italy to conduct joint training exercises with the Polish military as the situation in neighboring Ukraine shows no sign of easing.
An additional deployment of 150 paratroopers to Estonia, Latvia and Lithuania, respectively, will take place over the coming months.
With the announcement, the Obama administration is effectively sending a message that with all the talk of a "re-balance" in focus to the Asia-Pacific region, the exercises also show that the U.S. commitment to the NATO alliance is solid.
"It's a very tangible representation of our commitment to our security obligations in Europe, and the message is to the people of those countries and to the alliance that we do take it seriously," Pentagon spokesman Rear Adm. John Kirby said this week.
With Russia massing an estimated 40,000 to 50,000 troops under the guise of military exercises along its border with Ukraine, anxiety is running high among some of the newer members of NATO, themselves former states within the Soviet Union, regarding Russia's possible designs on territorial expansion.
Under the collective defense clause of the NATO charter, an attack on one member constitutes an attack on the entire alliance, thus obligating American involvement in any response to such an attack.
The exercises are a manifestation of that obligation.
"It sends a signal to (Russian President Vladimir) Putin his ambitions can't go as far as the NATO territory because we have this commitment to them," Nicholas Burns, a former U.S. ambassador to NATO, said in an interview with CNN on Wednesday.
Ukraine is not a member of NATO.
While the United States conducts exercises with the four countries on a routine basis, the Pentagon acknowledges the newest exercises are in part a response to the ongoing instability in Ukraine.
"These exercises were conceived and added on to the -- added on to the exercise regimen as a result of what's going on in Ukraine," Kirby said.
But are the exercises sending the right message to both Putin and U.S. allies in NATO?
Senior Republican members of Congress say they are a good first step, but require the necessary follow through by the administration.
"We should have them in Poland, Latvia, Estonia and make it clear this is not just a temporary measure," Rep. Peter King, a Republican of New York, told CNN in an interview. "One criticism I would have of the President is he's not up until now shown we're in this for the long haul."
"Do I think we could do larger NATO exercises, U.S.-led in a place like Poland? I do," said Rep. Mike Rogers, the Republican chairman of the House Intelligence Committee, in an interview with CNN's Wolf Blitzer. "This is a very good start and a very good sign to let Putin know that we won't tolerate, the United States won't tolerate any incursion into NATO states."
While the Pentagon will not say how long the new exercises will last, NATO is still exploring additional responses and measures the alliance can take with regard to Ukraine.
One former senior U.S. military officer told CNN that such exercises are important to maintaining the NATO alliance, but they will require more lift from European partners in the future.
"For the NATO countries, if they want to be reassured, they need to help with this by putting some real money towards their defense budgets," Gen. Richard Myers (Ret.), the former Joint Chiefs Chairman, told CNN. "They've been underfunding defense for many, many years for lots of reasons. And if they're really serious about this, they've got to help. It can't just be the U.S. alone."