I think the reason Russia fears the ABM’s in Poland is simple: the ABM site becomes a strategic nuclear tripwire. That system, like an early warning satellite, is a national resource of such importance that attacking it is akin to a nuclear attack – it is a MAD violation. Hence Poland fells insulated from invasion because our critical system is sitting there.

There is also a valid reason for the Patriots. If the Iranians wanted to nuke us, first they might use IRBM’s to take out the ABMs. The Patriots are adequate for defending the ABMs, hence preserving their strategic role.

Furthermore, Patriots are essentially point defense weapons (air defense 70km, missile defense 15km). A Patriot battery defending the ABM site does little for Poland’s overall air defense capability.