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Happy New Year -- we should hope -- because 2013 could prove a defining one on a host of interrelated challenges in the Greater Middle East, and elsewhere, that will have profound consequences for the United States and its allies for decades to come.

The challenges include Iran and its nuclear program, Syria and its transition to a post-President Bashar al-Assad future, Egypt and its government under the Muslim Brotherhood, the West Bank and its future under a Fatah-Hamas reconciliation, and the direction of Iran ally, Venezuela, after strongman Hugo Chavez dies.

These challenges could prove particularly, well, challenging for an administration that wants to reduce, rather than increase, the U.S. footprint in the region (“leading from...