The U.S. Marine Corps made news recently when two generals were forced to retire for not exercising adequate leadership while commanding marines in Afghanistan in 2012. The two generals were responsible for the large marine base that was attacked by a Taliban suicide team that managed to destroy six Harrier jets and damaged several other aircraft. Two marines died along with all of the fifteen attackers.
What was unusual about this is that in the American military, army and marine generals are rarely forced out of the service for poor performance in the combat zone. While the navy regularly relieves ship captains for poor performance, and the air force has a tradition of relieving commanders (colonels and generals) for not getting the job done (especially when nuclear weapons are involved), kicking them out of the service for these lapses is rare. The marines, however, do have a tradition of expecting more and this was another example of it.
The United States used to be far more demanding of its senior military leaders and civilian officials. For example, once World War II began (in 1939, two years before the U.S. got involved), there was a massive removal of peacetime commanders from ships and other senior commands in the army. The peacetime evaluation system selected officers who were well qualified to command in peacetime but not in wartime. This was recognized in the two years before the United States entered the war (with massive transfers and forced retirements of senior officers) and confirmed when so many more commanders had to be relieved when they proved to be incapable of handling their duties in actual combat. Since then there has been more of an effort to emphasize how good a commander is at keeping poor performance out of the news, not getting the job done. After September 11, 2001, for example, no one was fired for the poor performance in the American intelligence community. Same thing happened in 2012, when the U.S. ambassador was killed by al Qaeda in Libya. Senior officials responsible for this denied responsibility and all held onto their jobs.
Some other nations do still enforce performance standards. Russia has a long tradition of the "vertical chop," where several senior leaders in the same chain of command are dismissed (or even executed) when there is a screw up in their area of responsibility. For example, back in 2009, Russia replaced the head of its Strategic Missile Forces, Colonel General Nikolai Solovtsov. The official reason was that Solovtsov had reached the mandatory retirement age of 60. However, senior military commanders who are doing well are often allowed to keep going after age sixty. Solovtsov was apparently in trouble for other reasons as well. For one thing, he has been openly skeptical about reducing the Russian warhead inventory and apparently not too happy about current plans to reduce U.S. and Russian nuclear warhead holdings to about 1,500 each. Another issue that does not reflect well on Solovtsov was the effort to convert the Topol-M land based ICBM into a sea based missile (the Bulava). This missile recently failed during another test firing (its sixth out of eleven). While Bulava is a navy project, Solovtsov signed off on trying to convert the Topol-M. There was recently several dismissals in the Russian Space Agency after a string of satellite launchers failed. In the U.S. similar failures usually produce lots of devious press releases, not admissions of responsibility and resignations.