U.S. Secretary of State Hillary Clinton and British Foreign Secretary David Miliband (shown here Jan. 21 in Washington, D.C.) will be among the officials meeting in London this week to discuss Afghanistan and Yemen. Joshua Roberts/Getty Images hide caption

itoggle caption Joshua Roberts/Getty Images

A Yemeni soldier operates at the checkpoint on the northern entrance of the capital, San'a, on Jan. 13. Nasser Nasser/AP hide caption

itoggle caption Nasser Nasser/AP

George Mitchell (left) meets Israeli Defense Minister Ehud Barak in Tel Aviv on Thursday. Matty Stern/U.S Embassy, HO via AP hide caption

itoggle caption Matty Stern/U.S Embassy, HO via AP

On the Egyptian side of the Egypt-Gaza border town of Rafah, construction is under way of a barrier meant to stop the smuggling of goods and weapons to Gaza via underground tunnels. Israel has blockaded all of Gaza's other borders. Eyad Baba/AP hide caption

itoggle caption Eyad Baba/AP

Secretary of State Hillary Clinton listens to remarks by Jordanian Foreign Minister Nasser Judeh after their meeting Friday at the State Department. Tim Sloan/AFP/Getty Images hide caption

itoggle caption Tim Sloan/AFP/Getty Images

The massive Ataturk Dam (shown here in 1992), in southeast Turkey, harnesses water for one of the biggest irrigation and electric power schemes in the world. A drought and other factors have created an acute water shortage in the Middle East, and resentment in countries downstream from Turkey is growing. Ed Kashi/Corbis hide caption

itoggle caption Ed Kashi/Corbis

Adilla Finchaan, 50, checks her drought-stricken land in Latifiyah, about 20 miles south of Baghdad, in this photo taken in July 2009. Below-average rainfall and insufficient water in the Euphrates and Tigris rivers — something the Iraqis have blamed on upstream dams in Turkey and Syria — have left Iraq bone-dry for a second straight year. Hadi Mizban/AP hide caption

itoggle caption Hadi Mizban/AP

The Al Tarfa Desert Sanctuary near Al Qasr in remote western Egypt bills itself as a "luxury eco-lodge." Villagers are excited by the prospect of more tourists, but wary of changes to their lifestyle. Peter Kenyon/NPR hide caption

itoggle caption Peter Kenyon/NPR