I made the argument that his war may have started when his father shipped out but that's not when the war began. And that if the start of wars were marked by troop movements, particularly around national borders, then Pakistan and India would be in a never ending war. As would the US and Mexico. so what constitutes the beginning of a war?
The US has troops all over the world. That doesn't mean that there's a war going on. His father may have shipped out in 1989, but that wasn't due to any war going on whatsoever, just as there are a huge number of US troops in Germany and Japan, but we're not actually at war with either of those countries.
Your coworker seems to be unclear on the concept of the stationing of troops in a non-wartime capacity.
There was no war declared for the 1st Gulf War. Congress is the only body with the right to declare war and politically declaring war can be dicey, so there is hesitation to call for a full-on war. Instead they use circumlocutions to convey the idea of war without having to declare it. Hostilities occurred starting on January 16, 1991 when the US undertook the military operation Operation Desert Storm. Other countries have different criteria for declaring war.
2 August 1990 is when Iraq invaded Kuwait. US Soldiers were in Saudi Arabia on 7 August, 1990, as part of Operation Desert Shield. Desert Storm officially began on 16 January, 1991, when the Coalition started bombing Iraq. Iraq had been given until January 15, 1991 to withdraw from Kuwait. [Timeline from PBS] (http://www.pbs.org/wgbh/pages/frontline/gulf/cron/)