> An F-15 being shot down in Iran after weeks of strategic bombing of their anti-air defense systems is not a good sign.
Why? We don't know exactly what happened but its easy to imagine that Iran held some anti-air systems in reserve for this phase of the war. They aren't trying to defend a target, their goal was likely to stay hidden and wait for an opportunity. They could keep the radar off and use a passive sensor network to notify them when it was in range, then turn the radar on to get a lock for the shot. Or even just IR. Recall, the Houthis gave stealth F35s some near misses over Yemen, no doubt supplied and trained by the Iranians.
https://www.twz.com/air/how-the-houthis-rickety-air-defenses...
Why would that not be a bad sign? The US declared victory several times, but clearly Iran still has plenty of firepower to shoot down planes, and probably also ships in the Strait. If the US is incapable of preventing Iran from shooting ships and planes, how do they intend to win this?
It's absolutely a bad sign. One among many.
OP left a little to interpretation, but, I think, top of the list starts with 'mission accomplished 2.0' meme followed by increased US casualties ( though I suppose the exact order likely depends on your current disposition ).
It was pretty much a given that over time some of these airplanes would be shot down. There's no way to get every single MANPAD or even some of the larger anti-aircraft setups. A jet can even be brought down by a canon or a bullet given enough luck. We've had quite a few near misses, there's a video of an Israeli F-16 evading a surface to air missile, there have been the F-35 that was hit but managed to continue and land, there were countless drones shot down.
This was inevitable and just a question of time. Out of >10k sorties something is going to get hit. I've no idea what range the military planners expected and how we're doing vs. that.