From the beginning, the call to arms was highly uncertain. On Dec. 1, 2009, commander-in-chief Barack Obama orders 30,000 more Americans into battle in Afghanistan. But in the very next sentence, he announces that an American withdrawal will begin after 18 months.

Astonishing. A surge of troops — overall, Obama has tripled our Afghan force — with a declaration not of war, but of ambivalence. Nine months later, Marine Corps Commandant James Conway admitted that this decision was “probably giving our enemy sustenance.” This wasn’t conjecture, he insisted, but the stuff of intercepted Taliban communications testifying to their relief that they simply had to wait out the Americans.

What kind of commander in chief sends tens of thousands of troops to war while announcing in advance a fixed date for beginning their withdrawal? One who doesn’t have his heart in it. One who doesn’t really want to win but is making some kind of political gesture. One who thinks he has to be seen as trying but is preparing the ground — meaning, the political cover — for failure.

Until now, the above was just inference from the president’s public rhetoric. No longer. Now we have the private quotes. Bob Woodward’s book, Obama’s Wars, drawing on classified memos and interviews with scores of national-security officials, has Obama telling his advisers: “I want an exit strategy.” He tells the country publicly that Afghanistan is a “vital national interest,” but he tells his generals that he will not do the kind of patient institution-building that is the very essence of the counterinsurgency strategy that Generals McChrystal and Petraeus crafted and that he himself adopted.

Moreover, he must find an exit because “I can’t lose the whole Democratic party.” This admission is the most crushing of all.

First, isn’t this the party that in two consecutive presidential campaigns — John Kerry’s and then Obama’s — argued vociferously that Afghanistan was the good war, the right war, the war of necessity, the central front in the War on Terror? Now, after acceding to power and being given charge of that very war, Obama confides that he must retreat lest that very same party abandon him. What happened in the interim? Did it suddenly develop a faint heart? Or was the party disingenuous about the Afghan war all along, using it as a convenient club with which to attack George W. Bush over Iraq, while protecting Democrats from the charge of being reflexively antiwar?