As the negotiations over Iran’s nuclear program careen toward the finish line, tensions between U.S President Barack Obama’s administration and Israel remain high. The inability of the United States and Israel to reconcile their positions is not, as some critics contend, the result of Obama’s wavering commitment to Israel’s defense, but of two enduring and deep peculiarities of U.S. strategy: first, its expansiveness, and second, America’s uniquely idealistic strategic culture. These shape not only U.S. cooperation with Israel but also U.S. security partnerships around the world.

Unlike Israel, the U.S. has far-ranging, interconnected global concerns. How the U.S. deals with Iran reverberates outside the Middle East. Done badly, the U.S. approach to Iran might advance Israel’s security while degrading American interests elsewhere in the world. ...