Gulf Wars:

Medics or corpsmen were decently trained, but they may or may not have had blood on hand for wounded fighters, for example, or penicillin, or morphine. The military's portable, auxiliary, or mobile surgical units were not portable, auxiliary, or mobile. America improved the medicine so much that it would have taken every wheeled vehicle in Saudi Arabia to move a MASH (mobile army surgical hospital).

This lack of medical mobility likely delayed the kickoff of Desert Storm by 30 to 60 days. Thousands of people on both sides would be wounded or killed. Now, it turned out the Iraqi military was big on paper but not big on training, and morale wasn't any good, and they mostly rolled over when confronted.

Navy SEALs in Panama - just a year before the Gulf War - advanced high-level Special Forces medical care and learned to better stabilize patients. New techniques for transporting and using fluids and antibiotics were developed. Physicians didn't have much training at all in how to translate that into the field environment. Tactical casualty care was an application of the lessons learned based on data collected during the Vietnam War and analyzed with computers in the 1990s.

One of the important early changes on the battlefield was the resuscitation of patients, both pre-hospital and upon arrival at a medical unit. The availability and portability of blood products and blood transfusions have evolved much in terms of battlefield care. Today, stateside general surgery these days is minimally invasive and done through scopes. On the battlefield you still must make big incisions on large body parts like the abdomen. That's where additional trauma surgery training becomes vital for military-specific skills.