Since the end of the Cold
War, deterrence has receded as a policy pillar. The illogic of long and costly
wars that killed tens of thousands in the name of deterring hypothetical future
conflicts was manifest long before Saigon fell. Some of the Cold War’s titans,
including former Secretaries of State George Shultz and Henry Kissinger,
eventually repudiated
a nuclear weapons strategy predicated on “mutually assured destruction” — deterrence
in its most extreme form — in favor of a steady reduction in arsenals and
determined drive to counter nuclear proliferation worldwide. Since then, most presidents
have sought to perfect a much more measured form of deterrence. President
George H.W. Bush was chided for not deterring Saddam Hussein’s 1990 advance
into Kuwait, but his subsequent intervention fired a warning shot on
cross-border aggression that was heard around the world. President Bill Clinton
launched more than a dozen mostly small-scale military interventions and reflected near
the end of his tenure that “deterrence remains imperative.” George W. Bush
broke the pattern. Spurred by the 9/11 attacks, he took deterrence to a warped
extreme by launching preemptive war against Iraq’s non-existent nuclear weapons
program. He gave Saddam Hussein and his sons a 48-hour ultimatum
to leave Iraq, saying anything short of Hussein’s ouster would amount to craven appeasement
of a murderous dictator.

In reaction, Barack Obama,
particularly in his second term in office, has posited himself as the nation’s
first post-deterrence president. While Obama has been unafraid to go after
individual terrorists through targeted and lethal operations, he has grown
increasingly skeptical about mobilizing American force writ large to shape
geopolitics.

At West Point in late May, he
dismissed
the view that “America’s willingness to apply force around the world is the
ultimate safeguard against chaos” and pooh-poohed the notion that Washington’s
failure to act in Syria or Ukraine “invites escalating aggression in the
future.” The centerpiece of his foreign policy has been U.S. disengagement from
the wars in Iraq and Afghanistan, and a firm refusal to enter ongoing wars.
He has repeatedly trumpeted his commitment not to deploy ground troops, whether
in Libya, Syria, Ukraine, or now post-post war Iraq. He has decried the notion
that military action should be contemplated in places like Syria or Ukraine just because doing so “would look strong.” His view is undoubtedly informed by the
fact that some of his most formidable foes may be undeterrable — jihadists who
venerate suicide, fanatic regimes, and militant rebels with nothing to lose. And
let’s not forget that he’s been weathered by a largely futile effort to turn
around the Afghan war early in his term through dispatching extra troops.