The money quote is:
I am often characterized as “pragmatic.” I believe this is a very pragmatic proposal. I have found since taking this post that when it comes to missile defense, some hold a view bordering on theology that regards any change of plans or any cancellation of a program as abandonment or even breaking faith. I encountered this in the debate over the Defense Department’s budget for the fiscal year 2010 when I ended three programs: the airborne laser, the multiple-kill vehicle and the kinetic energy interceptor. All were plainly unworkable, prohibitively expensive and could never be practically deployed — but had nonetheless acquired a devoted following.My love affair with this SecDef continues. While this change might have been handled better, and I do believe that one reason to change the plan is to reduce the anxieties of Russia, which Gates underplays, the basic decision is a sound one.
And while it may not be politically acceptable these days to suggest that one is changing a policy to reduce the threat posed to Russia, it does follow from the logic of the security dilemma and my lectures in Intro to IR this week: that in anarchic system (no world government), countries must rely on themselves and that means if one country arms, then others will react, despite the stated good intentions of the first actor. So, Russia can only look at missiles (even defensive ones) on its borders as a threat and react accordingly. Will Russia consider naval vessels with anti-missile missiles parked in the Black Sea as less of a threat? Thus far, that looks likely.
Anyhow, making policy based on the costs and benefits of the various systems is the right way to go, even if one downplays one of the key benefits. Certainly better than making policy based on "theology."