..."There are more than 40 nations supporting the effort in Afghanistan," said a senior defense official speaking on background. "Many of the nations have caveats on how their forces may be used. This makes it unnecessarily complicated for commanders."

Some nations have placed restrictions on what their forces can do. Some countries will allow their forces to provide humanitarian assistance only. Others will allow their soldiers to participate in defensive operations, but not in offensive ones.

The NATO security assistance force should have one set of rules, or at least have a "minimal number of caveats," the officials said, making it easier for NATO personnel to work with their American and Afghan counterparts in the region...