FOR MUCH of the past 15 months, President Obama sought to advance his goal of a Middle East peace settlement through public pressure on Israeli Prime Minister Binyamin Netanyahu. The results were mixed. Mr. Netanyahu made significant concessions to the White House, including announcing for the first time his acceptance of Palestinian statehood and imposing a 10-month freeze on new construction in West Bank settlements. But Mr. Obama's attempt to insist on further Israeli retreats in Jerusalem and his aides' sometimes-harsh rhetoric produced a backlash both in Israel and in Washington -- and encouraged Palestinians to escalate their own demands.

With U.S. midterm elections looming, Mr. Obama tried a different tack Tuesday, showering Mr. Netanyahu with public praise and encouragement during a White House visit. The president said he believes that the Israeli leader "wants peace," praised his "restraint" on settlements and joined with him in calling on Palestinians to begin direct peace negotiations by September, when the settlement freeze expires. This switch may look craven to some of Israel's critics -- but in fact it is smart. By reaffirming U.S. support for Israel and pressing for direct talks, Mr. Obama has created an opportunity to put both Palestinian leaders and Mr. Netanyahu to the test and to discover who is serious and who is not about a two-state settlement.

Palestinian President Mahmoud Abbas has been assuring the administration's envoys that he is ready to make peace. But until now he has been under no pressure to deliver. Instead Mr. Abbas has watched from the sidelines as Mr. Obama battled with Mr. Netanyahu, while raising his demands on settlements to match those of the Obama administration. Palestinians have hoped that the United States would extract further concessions from Israel or announce its own plan for a final settlement between Israel and the Palestinians. Now Mr. Abbas has a choice: Begin direct negotiations in exchange for prisoner releases and other "confidence-building measures" that Mr. Netanyahu has been offering -- or show himself to be not so ready for peace, after all.

If talks begin, Mr. Netanyahu, too, will be challenged. Mr. Obama's counterproductive focus on issues such as Jewish housing in Jerusalem has allowed the Israeli leader to rally domestic support and delay spelling out where he stands on truly central questions, such as the borders of a Palestinian state and whether Jerusalem will be its capital. Mr. Netanyahu says that he needs guarantees that the West Bank will not become a base for Iranian influence and missiles aimed at Israel, as have southern Lebanon and the Gaza Strip. That's not an unreasonable demand. But what will he offer Mr. Abbas in return? Only direct negotiations between the parties will make that plain.