BOULDER — The short answer is Vietnam. The longer answer to What took so long for the CU Buffs to play Air Force again? is … well, like most things, it’s nuanced. It’s a mess of grey and old grudges, a cautionary tale of what happens when sports and politics get tossed into the same boiling pot and stirred like there’s no tomorrow. Denver Post fileAir Force split end Bob Farr grabs a 15-yard third-down catch between Colorado’s Rick Cleveland (20) and Randy Geist (15) at Folsom Field on Oct.