JERUSALEM — The late Palestinian leader Yasser Arafat once famously said that the wombs of Palestinian women were his "biological weapon", with a high birthrate that would outnumber Israelis and ensure the establishment of the Palestine nation.

Today, that "demographic firepower" is in the hands of Israel. A wave of migration from the former Soviet Union in the 1990s, combined with a soaring birthrate among Jewish settlers in the West Bank, have shifted the demographic calculus in the region. The Israeli birthrate is now just over three children per woman — as high as five for the ultra-Orthodox — compared to just under three per woman among Palestinians.

Israel's current population of 8.5 million has increased tenfold since independence in 1948. While the country's population statistics include East Jerusalem, the Golan Heights, and settlements in the West Bank that aren't recognized as Israeli territory by the international community, the demographic trend is unmistakable. After declining to 2.8 births per woman in the early 1990s, the Israeli birthrate rose to 3.1 last year. Analyzed by religion, it's now 3.1 for Jews, 3.3 for Muslim Arabs, and just 2.2 for Christian Arabs.

While statistics for the West Bank only are unavailable, unofficial estimates point to an average of 2.8 births per woman — lower than Israel's, and down from the remarkable 8 per woman of the 1970s. There are 2.6 million Palestinians in the West Bank in addition to the 220,000 living in East Jerusalem, which was annexed by Israel in 1967. That population also rose tenfold since 1948 but the increase has since slowed, compared to the influx of Jewish settlers who now number 400,000 in the West Bank and 350,000 in East Jerusalem.

Settlers seem to have taken the Biblical instruction to "be fruitful and multiply" literally, and represent the fastest-growing demographic in the region with a yearly population increase of 3%. While the United Nations has criticized the expansion of West Bank settlements as an obstacle to peace, the construction boom has created tensions within Israel over competition for limited living space.

Overpopulated?

Israel's surface area is roughly 21,000 square kilometers, slightly smaller than New Jersey. But its population density, at 366 people per square kilometer, ranks among the highest in the world. "We need 40,000 to 60,000 new apartments each year," says Alon Tal, a demographer at the Ben-Gurion University of the Negev. "This pace of construction puts our biodiversity at risk."

Israel will reach 15 million inhabitants in 2050 if the current birthrate and rate of immigration hold, with a density of 750 people per square kilometer — similar to the largest cities in the U.S. Other than the expanse of the Negev desert, where increased immigration is expected around the city of Beersheba, the rest of the country will effectively become one vast urban area.

These demographic trends worry not only locals, but also foreign powers seeking to relaunch peace talks between Israel and Palestine. The West Bank, just 5,600 square kilometers in size, is similarly small and overpopulated with scarce land and water resources, not to mention Gaza — a 365-square-kilometer strip of land with more than 1.8 million inhabitants and a birthrate of 5 children per woman. As if history and geopolitics weren't enough, a demographic time bomb is now added to the list of intractable issues to solve in the Israeli-Palestinian conflict.