January 27, 2008: The U.S. military knows the value of experience, and it's especially critical when one unit replaces another in a combat zone. While email has been very useful in getting the replacement unit up to speed on what the situation is, there's nothing like having someone stay behind for a few months to make sure the new brigade gets settled in. In some cases, NCOs and officers are asked to volunteer to stick around another few months, to see that the new guys don't make any of the mistakes the last crew did, or help to avoid new problems.

While volunteers can often be obtained, the U.S. Marines have taken some of the sting out that extra duty by providing an extra $500 a month, for those who agree to stay at least 90 days, beyond 365 day, to serve at a headquarters of a new unit coming in. The marines tend to prefer reservists for this duty, as they are older and more experienced than active duty marines of the same rank.

The other services have used similar bonus programs for those who stay longer. Ever since World War II, it's been known that some troops find it easier to stay longer in a combat zone. No two people are alike in the amount of stress and hassle they can handle.