How many military members actually see combat?

As a clerk in Vietnam, I was mostly confined to the compound but was shot at rocketed and saw people die.

I have a friend who is a Navy Seabee-equipment operator (EO1 in the USNR)
They were like “Equipment Operator? Trucks are equipment. You guys are on convoy detail.”

That isn't a true statement. I was in the Army and in Vietnam first tour as an advisor to Vietnamese Transportation units and 2nd tour as Battalion XO to a Transportation Battalion operating in the Qui Nhon, An Khe, Pleiku areas and we have an average on one convoy a day ambushed during the 6 months I was there. I followed that with another year as advisor. It wasn't an easy life for the truck drivers who were exposed every day.

Don't know why this 4 year old thread showed up in my email, buuuuut...
Don't tell recruits this. The battlefield is now 360 degrees and 'truck drivers' get engaged on the MSR's, medics haul them back in. Some people have assignments that do not require them to leave the operating base, but it's not a promise you can make, and they're just as susceptible to poorly targeted mortars in the DFAC as anyone.

If you are Marine infantry you're going to spend a lot of time outside the wire. If you are a Navy Corpsman, you're going to out with your infantry unit beyond the wire. If you are a truck driver your are gong to be combat logistics, so you'll be driving outside the wire to get supplies to units that are in foreward positions, which in Afghanistan means you are going to be hit with IEDs and ambushes, so you'll be going out in a combat armed convoy. I can't speak for the Army, but I'm pretty much convinced it's the same deal for them.

If you are Marine infantry you're going to spend a lot of time outside the wire. If you are a Navy Corpsman, you're going to out with your infantry unit beyond the wire. If you are a truck driver your are gong to be combat logistics, so you'll be driving outside the wire to get supplies to units that are in foreward positions, which in Afghanistan means you are going to be hit with IEDs and ambushes, so you'll be going out in a combat armed convoy. I can't speak for the Army, but I'm pretty much convinced it's the same deal for them.

I was a Lance Missile Crewmember, 1989-1991. Panama and Desert Storm happened on my watch. We did not deploy for either and stayed in Germany.

During the Vietnam war the troops that were actually in combat each day (in the 6 combat arms) was about 27% of the total force. The 6 are, 1-infantry....2-artillery....3-armor...4-combat engineers...5-aviation, and 6-special forces.

Everyone in the military may see combat. (Not too long ago a recruiting station was attacked.) The 3 branches you cited have a good potential of being in the mix of things. If you want to live life on the edge, be a Chaplain's assistant. You get to drive the Chaplain around the combat zone to visit the front line units. Many times you and the Chaplain, who often is not armed, travel without an escort. If you want to get some first hand knowledge of who may see combat, read narratives on the Battle of the Bulge.

Not true at all. Any MOS may see combat. Any MOS can get pulled for security. Infantry, combat medics and truck drivers are outside the wire all the time. Anyway, everything isn’t going to be counterinsurgency forever. Maneuver warfare and near peer competitors are the future. That’s why Army basic is much more intense than it’s been for years if ever. A friendly suggestion; sell your own great service, and don’t put down the other branches. My last assignment was a joint unit. By and large, people gravitate to the service that suits them. Not everyone belongs in the Navy. Definitely not someone who wants to do ground combat.