HALIFAX, Canada — At the just-concluded Halifax International Security Forum, top European and North American military and defense leaders gave little indication what they think will happen in Afghanistan. Indeed, they are waiting on U.S. President Barack Obama to announce the new U.S. strategy so that they can line up behind it.

Surge or no surge, 10,000 troops or 35,000, the rhetoric surrounding Obama’s decision assumes that what he decides will set the course not just for the U.S., but for its NATO allies. “I know that Afghanistan is on everyone's mind, with the president soon to announce his decisions on the way ahead for the United States and our partners,” said U.S. Defense Secretary Robert Gates in opening remarks at the forum.

Without that...