It's hard to top "last minute combat" with an image more vivid than that of Richard Montgomery, Benedict Arnold and Aaron Burr attacking Quebec on New Year's Eve in 1775 - in a blizzard - because their troops' enlistments expired the next day.
That's one way to honor the soldiers' contracts.
In the Civil War, there were some awful moments with expired enlistments, starting with Patterson's stillborn diversion of Johnston before Bull Run. And wasn't there a New York regiment that marched off the field at Bull Run the day its enlistments expired?
Comes Iraq and it's not an attack by midnight, nor is it militia leaving despite pleas and orders. Say hello to the "stop loss" order. It could also be called the "stay put" order. Look:
Critics argue that preventing soldiers from leaving the military at the end of their contractual obligation was a breach of trust, and undermined the concept of the all-volunteer military.
An interesting fix to a problem older than the Civil War. Not one than can stand long in a litigious society, however.