During my final enlistment period in the Army, I deployed to three hostile places. The last of those was Iraq, back in 91.
During the run-up to Desert Storm, I'd been following the news. Some of you remember all the gloom and doom: 4th largest army in the world, combat-hardened troops, chemical weapons galore, yada yada yada.
My other deployments were during "peacetime", though they didn't seem very peaceful to me. THIS, on the other hand, was very likely to be a WAR, which any rational person would believe to be FAR more dangerous.
So, once negotiations failed, and the war was obviously on, I was SURE - I mean absolutely CERTAIN beyond a shadow of a doubt - that I would not return home, that I WOULD die there.
.....and I accepted that, and went about doing what needed to be done. Basically, my mindset became, "OK, I'm done for. But, until then, I've got work to do, and others are depending upon me."
Not so much as a scratch. Didn't fire a single round into anything other than a berm, and didn't have a single round fired at me (except for a couple of Scuds that were shot out of the sky by Patriot batteries).
In retrospect, Desert Storm was the easiest of my deployments. Mind you, there were some side effects of my mindset which created some relationship issues later on, but we're celebrating our 24th anniversary in a couple of months, so that wasn't insurmountable either.