I’ll leave aside the technical difficulties of a missile defense; these are just engineering problems, most of which have already been solved, with the remainder having solutions understood and under development.  I’ll only write about some of the political factors involved in our country defending itself.

I operate in this post from this First Principle: we formed the social compact that created the US explicitly to do two things: one is to protect individual liberty and facilitate an environment within which each of us also could satisfy our individual responsibilities.  The other is to protect our nation as a whole from outside disaster.  A corollary to this is the defense of our friends and allies, since their health, independence, and freedom contribute to our own and so facilitate our defense.

A missile defense system is intended to support that second imperative—national defense—and missile defense in Europe (and in eastern Asia when the alliances can be arranged) is a component of that.

There are a number of objections to our having an active, and forward, missile defense capability.

• Russia is also critical of the plan, which it believes is really intended to counter its missiles.
• While it might seem logical for the US to want to have a defense against Russian missiles, it’s not so simple.  A new missile defense system aimed at Russia could undermine the balance between the nuclear powers, prompting Moscow to add to its arsenal and build up its own defenses.
• [P]lans have gained momentum in Europe with the signing of basing agreements in Poland, Romania and Turkey, as well as backing by NATO.  But Russia, while initially welcoming the plan, now strongly opposes it, especially the interceptors in the final stage.  Russia fears those interceptors could catch its intercontinental missiles launched at the US.

Aside from my (minor) meme that if the Russians don’t like it, it must be a good idea, whatever “it” might be, there are a number of reasons why these objections are silly.  Say, arguendo, that our anti-Iranian missile defense system does have the capability of countering Russian missiles.  This isn’t at all farfetched, since the end-stage of our missile defense system includes a capability against all ICBMs (Russia’s included).  The Russians don’t have any intention of attacking us or our allies.  Do they?  Since they…do not…their plaint that a defense system might interfere with their non-existent attack is a non sequitur.  Besides, if they do attack, our government has a duty to shoot down those missiles—as well as to respond with the total defeat of Russia and their war.

Deploying a functional missile defense system could push the Russians into adding “to its arsenal and build[ing] up its own defenses?”  They’re already doing that.  However, even in our current economic strait, this is an arms race Russia cannot sustain.  Russia’s economy is too dependent on oil and gas exports, and that economy already is failing (and not only due to falling oil and gas prices on the world market).  They don’t have the money.  Besides, this is a rerun of a play we’ve already seen under identical circumstances: the failure of the Soviet Union and its subsequent dissolution was contributed to heavily by their effort to sustain a missile and missile defense effort in the face of our earlier, Reaganite missile defense system development.

• [R]elocating missile interceptors planned for Poland and possibly Romania to ships on the North Sea, could be diplomatically explosive.

If setting ourselves to defend ourselves and our friends and allies is diplomatically explosive, that’s a problem for those with plans to attack us, not for us.

• It [Europe-based missile defense] would undermine prospects for further cuts in nuclear weapons—a priority for President Barack Obama—and could also hurt US-Russian cooperation on other issues of international importance.

We’ve reduced our nuclear capacity below military viability, already.  We should be rebuilding/modernizing, not engaging in further cuts.  Beyond that, this is another red herring.  Stipulating a need for further cuts anyway, a viable defense against nuclear (missile) attack can only facilitate a willingness to reduce or eliminate expensive, no longer viable weapons systems.  When facing an effective defensive system,  there are two major options: overwhelming it with massive numbers—an enormously expensive option—or improving penetration aids and developing offensive systems that bypass the defenses.  The latter option doesn’t require much of an investment in nuclear weapons.

Moreover, Russia isn’t cooperating with us on anything, so there’s nothing here to hurt.  See their active obstruction of our, and of international, efforts to stop the Iranian nuclear weapons development program.  See, also, their active support for, and consequent blocking of efforts to curb or replace, a Syrian régime that has butchered 60,000 of its people in the last 18 months.  After Afghanistan, their “cooperation” won’t be even be necessary there, and as it is, it’s an iffy cooperation: they’ve already tried to get Kirghizstan to stop letting us use their bases, and we had to greatly increase the rent to be able to continue.

OK, one technical item:

• Romania [is] a poor location for an interceptor to protect the US.  …the Polish site would work only if the US developed capabilities to launch interceptors while an Iranian missile was in its short initial phase of powered flight.

However, Romania is well situated to defend Europe from Iran—or Russia, or China.

Additionally, intercepting missiles during boost already is under development, and this isn’t as difficult (relative to interception in any other phase of flight) as it might seem (only detection and reaction times are somewhat compressed).  Missiles still boosting are not yet at maximum velocity (they are still boosting), and they’ve not yet released their warhead(s), which greatly increases the interception problem, nor have they yet released their decoys and other countermeasures, which also greatly magnify the interception problem.

There are no coherent political reasons for not deploying an effective, and extensive, missile defense system around the world.