The political crisis in Washington, sparked by the publication of inflammatory comments by General Stanley McChrystal, the overall commander of US and NATO forces in Afghanistan, culminated in the firing of McChrystal Wednesday morning and his replacement by General David Petraeus, the former US commander in Iraq.

McChrystal was summoned from Afghanistan to a White House meeting where he submitted his resignation over the publication of a lengthy article in Rolling Stone magazine, in which he and his top aides were quoted making disparaging references to President Obama and nearly all the administration’s top national security officials.

Obama accepted the resignation, and McChrystal left the White House immediately. After three hours of meetings with his national security council and Pentagon brass, Obama appeared before television cameras to announce McChrystal’s ouster and the nomination of Petraeus to succeed him.

In his brief remarks, with no questions allowed from the media, Obama emphasized that he remained fully in support of the program of military escalation and counterinsurgency warfare with which McChrystal is identified. He pledged to do “whatever is necessary to succeed in Afghanistan,” adding, “This is a change in personnel but it is not a change in policy.”

General Petraeus, who was McChrystal’s superior as head of the U.S. Central Command, was closely involved in the administration’s Afghan policy deliberations and fully supported the decision last December to dispatch an additional 30,000 US troops.