We will destroy Islamic militants, vows Barack Obama
Barack Obama has vowed to "degrade and destroy" the radical Sunni militant movement in Syria and Iraq that claimed this week to have taken the life of a second American journalist.
But he then characteristically signalled that he would not be rushed into military action by Islamic State (IS) or anyone else.
"Their horrific acts only unite us as a country and stiffen our resolve to take the fight against these terrorists," Mr Obama said during a one-day visit to Estonia. "Those who make the mistake of harming Americans will learn that we will not forget, and that our reach is long and that justice will be served."
There was no detail, however, on how he would tackle IS. Nor was there any indication if other allies might participate in any expanded military operations – or, crucially, whether these would extend to the launching of airstrikes against the movement's safe havens inside Syria.
And as he took questions at a press conference in Tallinn, Mr Obama's instincts for caution and preparedness over passion and haste were on ample display. "It's going to take time for us to be able to roll them back," he said.
"We know that if we are joined by the international community, we can continue to shrink [IS's] sphere of influence, its effectiveness, its financing, its military capabilities, to the point where it's a manageable problem."
However, British ministers have privately admitted that they are exasperated by the "lack of leadership" from Mr Obama.
One cabinet member said they had been surprised when Mr Obama admitted last week that he had "no strategy" for handling Isis. "We are looking for the leader of the free world to give a lead," the minister said. "So far, nothing."
Mark Pritchard, a former secretary of the 1922 Committee of Conservative MPs, said: "Yes, humanitarian support. Yes, intelligence support." But he added: "I think we need to go a step further and join the Americans with targeted airstrikes."
Joe Biden, the vice-president, went further than Mr Obama, saying that the US would follow the terrorists who have killed two American journalists "to the gates of hell".
The release on Tuesday night of a video of the beheading of the second journalist, Steven Sotloff, a freelance reporter, seemed timed to unsteady Mr Obama as he left Washington for Estonia, where he had intended to give his full attention to the crisis in eastern Ukraine and to offer security reassurances to the Baltic states.