In retrospect, the first meeting between U.S. President Barack Obama and Israeli Prime Minister Benjamin Netanyahu was destined to succeed. It was assumed that the two men were deeply divided on two key issues: Israel's relations with the Palestinian Authority, in particular Mr. Netanyahu's opposition to a "two-state solution," and dealing with Iran, which seems bent on acquiring a nuclear weapon capability. Yet Mr. Obama and Mr. Netanyahu went out of their way to show agreement in their positions. That may not last.

After being largely disengaged from the Israeli-Palestinian peace process during the Bush administration, the United States is posed to resume an activist role in the region. Mr. Obama recognizes that the festering conflict is a cancer, capable of not only deteriorating into war but also undermining U.S. interests elsewhere in the Middle East. Creating a durable peace between Israel and the Palestinians would eliminate a source of rancor and anger against Washington and could help transform perceptions of the U.S. throughout the Muslim world.

A key obstacle to the peace process is the spread of Israel's settlements. Palestinians — and much of the world — see the growth of settlements as an attempt to create "facts on the ground" that make it impossible for Israel to return territory claimed by Palestinians. Most Western nations, including the U.S., consider the settlements in the West Bank to be illegal under international law. Throughout his Washington visit, Mr. Netanyahu was told of the U.S. desire to see the growth of the settlements halted. Mr. Obama was blunt: "Settlements have to be stopped in order for us to move forward."