As American and Middle East leaders begin peace talks in Washington, public discussion in the weeks ahead is likely to center on borders, security, settlements and the fate of Jerusalem. But behind all of this, in the negotiators’ minds, a threat hangs like the sword of Damocles: Isn’t the Palestinian population growing so fast that, soon enough, it will outnumber Jews in the land between the Jordan River and Mediterranean Sea?

American presidents and Israeli prime ministers have issued dire warnings about this for years. Late last year, former President Bill Clinton, speaking in Jerusalem, chastised Israelis, saying: “Two things remain unchanged” since he was president: “geography and demographics. Palestinians have more children than Israelis have or can import.”

Former Israeli Prime Minister Ehud Olmert, speaking to Israel’s parliament in 2007, predicted “a demographic battle, drowned in blood and tears,” if Israel did not settle with the Palestinians.