All aboard -- or discord -- on Afghanistan?

When President Obama announced a new strategy for Afghanistan last month, his decision was supposed to end the contentious debate within his administration on how to conduct the war. It didn’t.

Obama settled the question of how many additional troops the United States would commit to the war this year -- 30,000. But on almost everything else, the debate between White House civilians and Pentagon strategists has continued without pause.

Obama says he’ll start bringing troops home in July 2011; Defense Secretary Robert M. Gates says the drawdown will be modest and could be postponed. Obama says we won’t be doing nation-building; Army Gen. David H. Petraeus says nation-building is inescapable. Vice President Joe Biden says the strategy is not counterinsurgency; the generals insist that’s exactly what they’re doing.

Even the least controversial piece of Obama’s plan -- the sped-up deployment of troops -- has gotten muddied. The target of getting 30,000 fresh troops into the war zone by the middle of 2010 has slipped at least two months, to the dismay of some Obama aides, although the Pentagon says it’s not a big deal because most of the force will arrive by July.

Administration officials insist that this isn’t confusion, just different perspectives. “It’s not surprising that people come at the policy with different views,” said a White House aide who spoke on condition of anonymity. “I think everybody’s on the same sheet of music.”

But it doesn’t sound like harmony. And the continuing differences could spell trouble for the president, his civilian aides and the military even before their first formal review of whether the new plan is working, scheduled for the end of this year.

If civilian officials and military officers continue describing the strategy in discordant ways, it could cause confusion among the U.S. and allied forces that are supposed to do the fighting. And if the military command and the White House have a more basic disagreement about what they hope to achieve, it could lead to a serious civilian-military collision when major decisions have to be made.

The most recent round of the argument was over the pace of the Pentagon’s deployment of more combat troops. Last month, Obama said the troops would be in place by the middle of this year. White House aides trumpeted that as a signal that the president was serious about getting the job done quickly, so they were alarmed when military planners said they couldn’t meet the deadline. Was the Pentagon saluting the president in public, only to chip away at his orders in private? The details weren’t as important as the potential rise of mistrust between the president’s men and the military command.

Both sides say that argument has now been settled, but it was only a preview of the coming debate over when a U.S. withdrawal can begin.

Obama and his aides have portrayed July 2011 as a turning point that’s fixed on the calendar: At that time, the number of U.S. troops (now headed for more than 100,000) will begin to drop. Biden, the most vocal war skeptic, has promised that the decline will be “steep.”

Not so, the Pentagon says. Gates has said the drawdown will be gradual, and even suggested that it might not begin by mid-2011 at all. “The president always has the freedom to adjust his decisions,” he noted.

In theory, Obama’s decision should have put that question on ice for 12 months. The president has given his generals a year to see what they can do with more troops -- but he’s also built himself an exit ramp if this year’s fighting doesn’t produce tangible progress, and the generals know it.

That’s why the next focus of the debate probably will be on how broadly Army Gen. Stanley A. McChrystal, the commander of U.S. and allied forces in Afghanistan, defines his mission and where he chooses to focus his troops.

White House officials, beginning with Obama and Biden, have tried to ban ambitious-sounding terms like “defeating the Taliban” and “counterinsurgency” from the military’s lexicon. Their aim is partly political -- to reassure anxious Democrats that Obama wasn’t signing up for an open-ended commitment. But the generals have objected on practical grounds: Without those words, they have no way of explaining the mission to their troops.

A more concrete test will come when McChrystal seeks approval for a major campaign in the Helmand River valley, a Taliban stronghold west of Afghanistan’s second-largest city, Kandahar.

Some in the military have talked up an offensive in Helmand as a “demonstration project” -- an experiment to show that McChrystal’s plan can succeed, just as military success in Iraq’s Anbar province in 2007 bolstered confidence in that war. If U.S. forces can defeat the Taliban in Helmand, the argument goes, then McChrystal will be able to assert (in the late-2010 review) that his plan is working.

But McChrystal has to sell the idea to the White House first. Obama agreed to a strategy focused on protecting the country’s population centers, and Helmand is mostly rural. In the military’s view, defeating the Taliban in Helmand is key to rooting it out of from Kandahar. But to skeptics, a big campaign in a rural valley may look like overambitious counterinsurgency.

Aides say Obama is taking a more active role in decisions in Afghanistan now that he’s gone through the long process of deciding on a strategy. McChrystal’s weekly progress report now goes straight to the president, something that wasn’t happening last year. So this will be Obama’s decision too.

Debate over war aims and strategy is a good thing, of course. But the reason Obama put himself and the nation through all that deliberation last year was to build a consensus behind a sensible plan. Now that he’s got one, he ought to see if he can get his aides to agree on what it means -- and give McChrystal a chance to make it work without so much sniping along the way.

doyle.mcmanus@latimes.com