Question for the day

It’s easy to think of examples where great powers stayed in in some foreign war too long, and with the benefit of hindsight, it’s clear that they would have been better off getting out sooner. Examples might include the United States in Vietnam, France in Algeria, Britain and the Soviet Union in Afghanistan, or Israel in southern Lebanon.

Similarly, it’s easy to think of wars when states suffered early setbacks, chose to stay the course anyway, and ultimately succeeded. World Wars I and II, Korea, and the Boer War might be examples of this category, and some would place Iraq in this category too (although I wouldn’t).

Finally, I can think of several cases where states chose to get out of trouble quickly when things turned south, and never regretted it.  The United States got out of Lebanon after a suicide bomber destoyed the Marine barracks there in 1983 and it withdrew from Somalia in 1993 following the Black Hawk Down incident, and withdrawal didn’t have particularly significant strategic consequences in either case.  More importantly, staying longer wouldn’t have been worth it in any case. 

So here’s my question: Are there good historical examples where a great power withdrew because a foreign military intervention wasn’t going well, and where hindsight shows that the decision to withdraw was a terrible blunder? If there are plenty of examples where states fought too long and got out too late, are there clear-cut cases where states got out too early? 

For a case to qualify, you’d have to show that early withdrawal led to all sorts of negative consequences that might otherwise have been avoided. Hawks normally argue that getting out will embolden one’s adversaries, undermine one’s credibility, or jeopardize one’s geopolitical position, but how often does any of these anticipated misfortunes really happen? Or you could argue that the withdrawing state was very close to winning but didn’t know it, and that "staying the course" would have worked if they had just held on a little longer.

One possible candidate is U.S. involvement in Afghanistan in 2002-2003, but even that case isn’t clear-cut. Many experts now argue that our current troubles there could have been avoided had we kept our eyes on the ball in 2003 and concentrated on building an effective Afghan government, thereby preventing the Taliban from making a comeback. The main problem with this line of argument is that the United States didn’t really "withdraw" from Afghanistan (and certainly not because things were going badly). Instead, we just drew down our forces so we could go invade Iraq. Also, it’s not obvious that greater effort back then would have produced a markedly different situation today, although it is certainly possible.

In any case, my question still stands: How often has early and rapid strategic withdrawal from a war of choice lead to disastrous results for the withdrawing power? Is staying too long the greater and more common danger? And can anyone think of some good examples?