There's a debate going on in the U.S. Army Ranger community over whether combat experience is a suitable substitute for ranger training. In peace time, the army tries to send at least half of its combat NCOs, and most combat officers, to the two month Ranger school. You have to volunteer to go, but having successfully completed the school is a major factor in deciding who will get promoted. If you want to make the army a career, and you are in a combat branch (especially infantry), Ranger School is a must. But not so much anymore.
Since 2003, most veteran combat troops have served multiple combat tours in Iraq or Afghanistan, and have not had time, or the inclination, to attend Ranger School. This has upset many senior army commanders, who believe that the ranger training is essential for maintaining high quality leadership. But many combat veterans believe that Ranger School was mainly a way to find out, in peacetime, who would most likely perform well in combat. With real combat experience available, why waste time on a time consuming and strenuous substitute? Those backing the Ranger School insist that the training covers leadership and other useful skills. The combat vets respond by pointing out that they are always training, when they aren't in combat, and do not have to spend another two months away from their families in order to upgrade their leadership skills.
In some units, officers and senior NCOs lean on promising young men to go to Ranger School, so they can be promoted more quickly. These guys tend to respond by pointing out that they can do the job, and that if the army doesn't want to promote them, they will not re-enlist, and take their chances with the civilian job market. The pro-ranger crowd think they have the advantage, with the high unemployment rate and not many jobs requiring combat experience. Some officers and senior NCOs are noting that this pressure play is not good for morale, especially among some of the most valuable troops in the army (young guys with lots of combat experience and an obvious talent for leadership.)