The casualty cost of breaching the network around key installations, where it will undoubtably be supported by his air force, AWACS and other elements. With all others equal, the defenders SAM network may prove to be the straw that breaks the camel's back.
Hang on, if a strike package has just penetrated your IADS and hit a C4I node, and taken 20% casualties to do so (very high casualty rate), look at the disparity in effect. The attacker has lost ~2 platforms. The defender has just lost his ability to communicate with his advanced formations just as a large offensive has been launched against him. Who has lost more? Do that 10 times and the attacker has lost 20 platforms, and if they are a comparable power to the AWAC's, fighter & S-300 equipped IADS defender they have 100+ platforms with comparable or better ISR capability (because they didn't spend all of their pennies on a defense centric IADS). They've taken 20% casualties, the defender's entire system (not just the IADS) can no longer function intelligently at a theater level. What that means is his formations in the field will be out-maneuvered, out-fought and slaughtered.
I believe you said 8 batteries, 3~4 batteries per battalion thats ~2 battalions.
How is it useless, when it can be used to give at least limited additional protection to your troops?
Thats the difference between tactical effects and strategic effects. On a tactical level it might do some good, but by that point you've lost on a strategic level i.e. your C4I infrastructure is toast. The point isn't to do your best, its to win, and by that point you've lost.
I don't understand. Are you operating on the assumption that having SAMs implies having an inferior air force?
I'm operating on the assumption that if you've invested that heavily in your IADS you are either at a competitive disadvantage in the air or your defense centric anyway. Look at the US, how dense is their IADS? How many PATRIOT batteries are operational night now in CONUS? You know why inferior powers have superior IADS, because the US have invested heavily in offensive capability.
What stops the network from reforming itself? From maintaining redundant additional mobile command posts that can quickly replace the one you destroyed and pull up additional assets to plug the breach?
There is a major point your missing, and its what i meant by a dis-jointed view of modern warfare. Its not air force vs IADS, its entire war-fighting system vs entire war-fighting system. Even if mobile AD command posts take up some of the slack (which would be easy pray considering their EM footprint), you have impaired the whole war-fighting system at the head. That will have strategic effects i.e. on every other aspect of the conflict. The loss of 15% of the attackers AF order of battle (huge, worst case losses) will have moderate tactical effects in this type of scenario, at best.
Wait, are we talking about C2 nodes of the IADS or C2 nodes of the opponents forces in general?
Both!
So..... you agree with my argument that IADS can be used to effectively protect your ground forces and C2 from enemy air raids?
No, not on their own, unless your other military arms aggressively win the conflict.
I'm not saying SAM's are sh%t and anyone who buys them are idiots, that would mean the majority of the planets armed forces. I'm saying that the money is much better invested in assets that will actually win you air superiority over the other guy. IADS like all other forms of defensive fortifications do not constitute a war-fighting strategy on their own.
I don't see where your assumption comes from that I'm advocating using an IADS instead of anything. I'm saying that an IADS needs to be used in addition to all other assets, and as such would give a critical advantage in several ways:
1) Tactical air defense capabilities to even advancing ground troops.
2) Strategic air space coverage.
3) Limitation of the opponents air force to act freely.
4) Point defense of key installations.
Again this is a defense centric view. What should be limiting the opponents air forces freedom of action should be your air force hitting their C4I & logistical infrastructure and destroying them on the ground or over their airfields. Same with every other parameter. Sure some sort of GBAD is needed, even for an air power as capable as the US. But GBAD should only be intended to handle leaker's that survived your fighters & strikers.
Again, usually nations that invest heavily in the biggest, baddest, scariest IADS are usually at a competitive disadvantage in the air, and they usually loose. Look at the Israeli's, outnumbered and surrounded by hostile states did they invest heavily in defensive AD systems? No, they made sure they had the assets, people and tactical doctrine needed to take the initiative when the time came. It was their numerically superior enemies who invested heavily in GBAD, and it was their numerically superior enemies who lost.
The principle of offense.