It took a tragedy on the scale of the downed Malaysian airliner to amplify what President Obama and his national-security team have been saying for months—that Europe cannot afford to ignore the wolf at the door that is Vladimir Putin.

Standing before reporters in the White House briefing room, the president on Friday called the tragedy in eastern Ukraine "a wake-up call" to the continent and warned that the loss of 295 innocent lives, most of them European citizens, proves there are "consequences" to what he termed an escalating conflict "that is not going to be localized, it is not going to be contained."

Obama had announced a new series of sanctions on Russian financial, energy, and defense entities just a day before a suspected missile strike took down Malaysia Airlines Flight 17 near Ukraine's border with Russia. And, although the White House made a point of noting that the new penalties had been coordinated with the European Union, the E.U. again failed to go as far as the U.S. in targeting key industry sectors and wealthy industrialists with ties to Putin.

That has been the story since Russia first seized Crimea earlier this year: Obama taking a harder line on sanctions, with Europe, concerned about the effect such moves would have on its own regional economies, dragging its feet. It has been another source of tension, along with the U.S. global spying regime, between the administration and Germany, which has strong economic ties to Russia. Angela Merkel, the German chancellor, said Thursday that any talk of tougher E.U. sanctions was "premature."

But Thursday's incident may be changing the calculus. At a meeting of E.U. ambassadors Thursday evening, several member nations called for ramping up the penalties, the Financial Times reported, which quoted one diplomat as saying, "It will be easier [now] to get agreement on individual measures."

A tougher stance by Europe has long been viewed as a needed cudgel to force Putin into backing off in Ukraine. Obama has largely been restrained in criticizing his European allies, although at a meeting of the G-7 in Brussels in June, he said he was disappointed that France was going ahead with a $1.6 billion deal to sell warships to Moscow.

But it was clear in his first extended remarks on the downed airliner that the president expects the out-of-the-blue attack on MH 17 to spur further, more severe action. He made a point, early in his remarks Friday, that most of the passengers on the plane were Dutch and that it was "destroyed in European skies."

The event, he noted, "sadly brings home the degree to which the stakes are high for Europe, not simply for the Ukrainian people."

His words came after Hillary Clinton, his former secretary of State, urged Europe to get tough in a PBS interview Thursday. If evidence links Russia to the missile strike, Europeans should immediately act on three counts, Clinton said: "One, toughen their own sanctions. Make it very clear there has to be a price to pay."

Second, Clinton said, they needed to accelerate efforts to find alternatives to Gazprom, the Russian state-owned gas company that serves as a major energy supplier to Europe. Third, she said, the E.U. needed to do more in terms of material support to the Ukrainians.

"Europeans have to be the ones to take the lead on this," Clinton said.

Greater European involvement would allow Obama some needed space in dealing with Putin, defusing the mano-a-mano dynamic that has marked the crisis, while allowing him to practice the kind of George H.W. Bush style of consensus-building diplomacy he and his team favors.

The hope is that the international outrage, combined with further penalties, will finally convince Putin that he has overplayed his hand. And as terrible an event as the crash as was, it may ultimately mean that Obama no longer has to be the loudest voice in the room. For a White House besieged by chaotic events at home and abroad, that could come as a welcome development, albeit one that comes at an awfully high cost.