[dexen]

It takes a good while to detect preparations for an attack with this kind of weapon & take the decision ("Mr President, the station has slightly shifted around, should we nuke it now?"), and it takes long time for any physical weapon to reach it.

A decent weapon would be space-burst version of ICBM. For intercontinental ground attack, the flight time is typically 20 minutes, but the most reasonable spot for the station is a geostationary orbit - some 36'000 km above equator. With a sensible speed on the order of 8km/s, it would take our missile around 1h25m to reach geostationary orbit assuming a naive straight-up trajectory; with any realistic trajectory it would take way longer. The space weapon would be able to rain terrible destruction in the meantime with impunity.

An alternative would be using ground- or space-based lasers, which give near instantaneous hit, but you'd need to precisely hit a proper part to guarantee fast disabling of the weapon. Merely hitting a random spot on the dish would probably not destroy it outright. You still have to account for the time to make the observations & take the decision. And the current breed of [high power] lasers is single-use only due to the destructive nature of generation of the large energy needed.

[adrianN]

That's all true, but a 2h window for destruction of single targets is not very useful against a modern military. There are enough ICBM silos that you can't destroy all of them before someone kills you DEATH STAR and then you still have to win the war that follows.

[AstralStorm]

Indeed, it is not a useful weapon in an all out war. I'd expect it to be used as surgical strike capability instead. Special operations. You can blame its use on inclement weather due to amount of electric charge this will paint on anything in path and resulting lightning storm.