Like Ronald Reagan's famous call in 1987 demanding that the Berlin Wall be torn down, President Bush expressed his concern last week about Israel building a barrier along the West Bank.
The "separation fence," under construction for a year, will run for hundreds of miles using a mix of 10-foot-high walls, razor wire, and deep trenches. It may already be serving its main purpose of blocking would-be suicide bombers from entering Israel.
But for Mr. Bush and others, the barrier is also hindering the "road map" peace process by carving up large portions of land that should eventually be in a Palestinian state.
In his meeting with Prime Minister Ariel Sharon Tuesday in Washington, Bush should at least ask for a firm commitment from Israel that it will not use the barrier as a political boundary in coming negotiations.
Moreover, Bush must make sure the fence doesn't snake farther and farther into the West Bank as it is built, cutting off Palestinians from Palestinians, and effectively annexing more occupied land. (Israel won't reveal the fence's final course.)
A future Palestinian state cannot be so emasculated and small that it's not viable for living or governing. Israel's security depends on having a healthy Palestinian state as a neighbor.