“The Americans were unwilling to escalate militarily,” said Husain Haqqani, a Pakistani ambassador to Washington during the Obama administration. Even when President Barack Obama ordered a raid on Osama bin Laden’s property in Abbottabad, Pakistan in 2011, Mr Haqqani added: “A major concern was: What if Pakistan takes revenge and this becomes some kind of all-out war? ?”
In 2007, US officials, including Mr. Bush himself, said Iran was equipping Iraq’s insurgent Shia militias with improvised missiles and deadly roadside bombs with an explosive-shaped penetrator that could smash through most US vehicles.
Senator Joseph I. Lieberman, a Connecticut independent, was among those who called for a military response, saying Iranian leaders could not have immunity from training and equipping people to enter and kill Americans. mr. Bush, who had already controlled two wars, never struck.
In fact, during the Korean War, the United States shied away from taking the fight to an enemy who attacked its forces directly. After American troops advanced near North Korea’s border with China in the late 1950s, Beijing sent hundreds of thousands of troops south to push the Americans back. Gene. Douglas MacArthur asked for permission to bomb bases, bridges and factories in China. But President Harry S. Truman rejected the idea and heeded the advice of other commanders who said an extended war could attract the Soviet Union and outrun the United States in the region.
The Soviets nevertheless sent fighter jets to help the US Air Force fight over Korea. Although Moscow denied its involvement and even marked its planes in North Korean colors, the United States suspected the truth – but chose to look the other way.
Perhaps the most obvious counterexample is the Vietnam War. Two U.S. presidents, Lyndon B. Johnson and Richard M. Nixon, ordered major military operations beyond Vietnam’s borders, into Laos and Cambodia, to close off supply routes and bases in the jungle known collectively as the Ho Chi Minh Trail.