President Obama’s decision to engage in a lengthy battle to defeat the Islamic State in Iraq and Syria reorders the global priorities of his final years in office. The mystery is whether it will deprive him of the legacy he had once hoped would define his second term, or enhance it instead.
Until now, Mr. Obama’s No. 1 priority in the Middle East has been clear: preventing Iran from obtaining a nuclear weapon.
Israeli officials, who by happenstance arrived in Washington this week for their regular “strategic dialogue,” immediately argued that ISIS was a distraction from that priority. Their fear is that the Iranians, finding themselves on the same side of the fight against ISIS as the United States, would use it as leverage to extract concessions from the president.
“ISIL is a five-year problem,” Yuval Steinitz, Israel’s strategic affairs minister, said a few hours before Mr. Obama addressed the nation on Wednesday night, using the acronym the Obama administration employs to describe the Sunni extremist group. “A nuclear Iran is a 50-year problem,” he said, “with far greater impact.”
Other Israeli officials warned the Obama administration that the new American operation would bolster Iran’s ambitions for regional dominance.
Mr. Steinitz may prove to be right. The Bush administration’s decision to invade Iraq 11 years ago distracted it from many things — notably the war in Afghanistan — and Iran used that time to vastly expand its capacity to produce nuclear fuel. But there is a countertheory as well: that a president who for five years made clear that he was looking for a way out of the bog of the Middle East may have a chance to re-establish American credibility in the region if the strategy he described on Wednesday night is well executed.
“If this goes well, and the United States is seen as acting effectively, it could generate political capital,” said Richard N. Haass, who served in the administration of the first President George Bush — the coalition-builder Mr. Obama says he most admires — as well as that of George W. Bush. “There’s the chance it will be something of an investment in the region. But that is going to require constant rudder checks, to make sure the administration’s broader goals do not go off course.”
It is the fear of veering off course that most haunts Mr. Obama’s current and former top national security aides. Even before the rise of ISIS, they looked at the calendar and worried.