Bergdahl, who was captured in Afghanistan 2009, and Altaie, missing in Iraq in 2006, are both thought to still be alive and in enemy captivity. The Haqqani Network, the militant group holding Bergdahl, regularly releases propaganda videos featuring the 25-year-old soldier, who looks increasingly haggard and frightened.

Yet the missing soldiers are largely invisible here at home. The White House and Pentagon rarely mention the two men and have made clear that they won't consider paying ransoms or freeing prisoners in exchange for the men's release, as Israel has done.

The difference between Israel's national obsession with Shalit--and its willingness to pay such a price to win his freedom--and the American indifference to Bergdahl and Altaie underscores a fundamental difference between the two societies. In Israel, where all citizens serve, the connection between nation and military runs deep. In the U.S., most Americans have no firsthand connection to the all-volunteer military, whose bases are located outside major cities and whose troops are largely invisible to the general public.

"The fact that we do now have an all-volunteer force which is culturally separated from so much of middle-class America and the geographic and population centers of America contributes to a general lack of concern for these wars and the people who have gone missing fighting them," said Michael Allen, a Northwestern professor and author of Until the Last Man Comes Home, a history of the POW movement in the U.S. after the Vietnam War. "There's just not much more interest anymore in talking about these wars."

That has led to an enormous substantive difference in the ways the two countries treat missing soldiers. Israel has a stated willingness to negotiate with terror groups and has, in the past, freed hundreds of Palestinian prisoners simply for bone fragments capable of confirming that a missing soldier was dead. In the U.S., successive presidential administrations have flatly refused to bargain with militant groups. Bergdahl's captors in Afghanistan, for instance, have floated exchanging him for prisoners held at Guantanamo Bay and other U.S. facilities, but Washington has ruled out any such trade.

Politically, the issue also resonates very differently in the two countries. Israeli Prime Minister Benjamin Netanyahu made freeing Shalit one of his top foreign-policy priorities, and polls show that his popularity has soared in Israel because of his success in winning the soldier's freedom.

In Washington, by contrast, the White House press secretary issued a muted and brief response to the Shalit's release, telling reporters that the administration was "pleased" the soldier was free.

The Romney and Perry campaigns declined to comment on their views of the Shalit trade or whether the U.S. should consider making similar exchanges to gain the release of Bergdahl and Altaie. Spokespeople for key lawmakers like Sen. John Kerry, D-Mass, the chairman of the Senate Foreign Relations Committee, and Rep. Ileanna Ros-Lehtinen, R-Fla., the chairwoman of the House Foreign Affairs Committee, also declined comment about either Shalit or the missing U.S. soldiers.