The move itself is symbolic (and long promised), air and naval based X-55 cruise missiles can do the same job with 2k km range.
Too bad Frank-Walter Steinmeier did not condemn as "the wrong signal at the wrong time" US fit of gun boat diplomacy when few months ago US had sent Arleigh Burke-class destroyer with simular to X-55 Tomahawks to the Black Sea, few dozen km from the Russian soil.
The Iskanders don't have any real prospect of shooting down incoming ICBMs or the missiles the US is promising to install.
It would make as much sense for Medvedev and Obama to square off in person for a round of fist waving and random name calling.
Iskanders are surface to surface, and are supposed not to allow the ABM missiles to take off the ground and/or deny them radar guidance, increasing chances for retaliatory stike using land based ICBMs.
If they're just sitting on fixed platforms in the open - that's a little silly and pointless, isn't it?
At least if I was developing it I'd put in that capability and build the munitions. The Russians are shrewd weapons makers and I assume they would do the same.
I'd also give it a Surface-to-Air capability -- but that's just me. :-) A doo run-run-run, a doo run-run
