In vowing in Estonia on Wednesday to defend vulnerable NATO nations from Russia "for as long as necessary," President Obama has now committed the United States to three major projections of its power: a "pivot" to Asia, a more muscular presence in Europe and a new battle against Islamic extremists that seems very likely to accelerate.
American officials acknowledge that these three commitments are bound to upend Mr. Obama's plans for shrinking the Pentagon's budget before he leaves office in 2017. They also challenge a crucial doctrine of his first term: that a reliance on high technology and minimal use of a "light footprint" of military forces can deter ambitious powers and counter terrorists. And the commitments may well reverse one of the critical tenets of his two presidential campaigns, that the money once spent in Iraq and Afghanistan would be turned to "nation-building at home."
But the accumulation of new defensive initiatives leaves open the question of how forcefully Mr. Obama is committed to reversing the suspicion, from Europe to the Middle East to Asia, that the United States is in an era of retrenchment. In his travels in Europe this week and a lengthy tour of Asia planned this fall, the president faces a dual challenge: convincing American allies and partners that he has no intention to leave power vacuums around the globe for adversaries to fill, while convincing Americans that he can face each of these brewing conflicts without plunging them back into another decade of large military commitments and heavy casualties.