For 70 years American Presidents from both parties have sought to thwart Russian influence in the Middle East. Harry Truman forced the Red Army to withdraw from northern Iran in 1946. Richard Nixon raised a nuclear alert to deter Moscow from resupplying its Arab clients during the Yom Kippur War in 1973. Even Jimmy Carter threatened military force to protect the Persian Gulf after the 1979 Soviet invasion of Afghanistan.

So it says something about the current Administration’s strategic priorities that it is having trouble...