With a little more than a month to go before a crucial national election, the wheels are coming off the Obama administration’s national-security credentials.

The coordinated attacks on the US consulate in Benghazi, which killed our ambassador and three other Americans — and the worldwide explosion of assaults on our diplomatic installations elsewhere in the Muslim word — have vividly exposed the hollow core of the president’s foreign-policy “reset.”

It was just a few weeks ago at the Democratic national convention that Obama confidently declared that “al Qaeda is on the path to defeat and Osama bin Laden is dead.” And yet, on the 11th anniversary of the 9/11 attacks, al Qaeda struck again against our lightly guarded consulate in Benghazi, where ambassador Chris Stevens was murdered — an attack, it now turns out, the United States had ample reason to suspect was coming.

The truth is, al Qaeda has been reforming in North Africa since the start of the “Arab Spring,” and its adherents and sympathizers now hold prominent positions in such crucial nations as Egypt, where our embassy was also attacked last month. Further, al Qaeda elements were among the Benghazi-based rebels who (with Western assistance) toppled the former Libyan strongman, Moammar Khadafy and have plagued that nation’s new government ever since.

Further, Ambassador Stevens had every reason to fear for his life in the lightly guarded consulate, as his personal journal (found by CNN after the attacks) made explicit. At State Department insistence, there were no Marine guards present, although Stevens was accompanied by two former SEALs, who died with him.

And there have been reports that Stevens was involved in supervising a clandestine intelligence operation that was trying to locate and secure some of the deadlier weapons floating around the chaotic country in the wake of Khadafy’s overthrow.

At first, the administration risibly claimed that the assaults were inspired by a You Tube trailer for an apparently nonexistent film, “The Innocence of Muslims,” which lampooned the origins of Islam. The White House sent stooges like Press Secretary Jay Carney and, worse, UN ambassador Susan Rice, before the public to blame the carnage on understandable Muslim “outrage.”

More chillingly, its response was to the blame the filmmaker, an Egyptian-born Coptic Christian living in the Los Angeles area. An ever-obliging news media promptly hunted down the man, Nakoula Basseley Nakoula, and — after Obama went to the United Nations and solemnly proclaimed that “the future must not belong to those who slander the prophet of Islam” — the feds threw him in jail on the pretext of a parole violation.