really depends on the stakes now doesn't it? In a total war situation massive, indeed nearly total losses, were expected. Against the North Vietnamese we lost literally hundreds of aircraft to combat causes and a lot of aircrew to go with them. American pilots shot down knew that mistreatment was certain in North Korean, Chinese, and North Vietnamese hands in both of the Korean and Vietnam Wars. So if the stakes are high enough, very high levels of loss are accepted.
On the other hand, a single full scale airstrike against Syrian targets during the US intervention in Lebanon in the 1980s resulted in one aircraft shot down with 1 aircrew killed, 1 captured and the US negotiated to get him released and withdrew from the conflict
So the stakes really matter
The US Air Force in the 1990s, even after the post Cold War draw down is very formidable, and very very good at destroying air defense networks and interceptor forces. It is their first mission during wartime or major interventions.
So the defenders are going to need a very powerful defense indeed