In a speech on Thursday, Hillary Rodham Clinton outlined a strategy for fighting the Islamic State that shows significant differences with President Obama’s. Some of her ideas make sense; others are familiar retreads, previously rejected, that remain problematic. But her speech gave voters her vision for dealing with terrorism after the Paris attacks. The Republican candidates have offered only destructive ideas like closing mosques, barring refugees and sending thousands of American troops to the battlefield.

Mrs. Clinton has a record of being more hawkish than Mr. Obama on America’s role in the world, and that came through in her comments to the Council on Foreign Relations. It was a more polished performance than her rocky showing at Saturday’s Democratic debate.

Unlike President Obama, Mrs. Clinton supports a no-fly zone over northern Syria, close to the Turkish border. This also offers the clearest contrast with her rivals for the Democratic presidential nomination. Senator Bernie Sanders and Martin O’Malley both say a no-fly zone would be unworkable and deepen American involvement. Mrs. Clinton argues that in addition to providing a safe haven for Syrians fleeing the bombs of President Bashar al-Assad and severing Islamic State supply lines, it would give the United States leverage in negotiations with Russia and others over a political settlement to Syria’s civil war.

Since the war began in 2011, the Obama administration has rejected proposals for a no-fly zone because they would require a significant military commitment: knocking out Mr. Assad’s air defenses, mounting an extended American air patrol and stationing ground troops to protect the zone and the refugees.