The Pentagon has moved a little closer to its eventual goal of a complete US missile-defence umbrella, carrying out a successful trial above the Pacific last week.
According to a Raytheon release, Standard interceptors launched from the Aegis cruiser USS Lake Erie destroyed both a "ballistic-missile target in space" and a "cruise missile threat at lower altitude," in simultaneous engagements.
The suborbital ballistic, launched from Kauai, was knocked down by a SM-3 Block IA "kill vehicle", the latest in Raytheon's Standard line, while the easier aeroplane-delivered subsonic cruise target was nailed by an older SM-2 Block IIIA variant.
"SM-3 represents a truly global missile defense capability," said Jim Maslowski, Raytheon Missile Systems international programs vice president. "SM-3 can leverage the deployed base of Standard Missile, which is in operation with 13 nations worldwide. SM-3 really fits into the chief of Naval Operations' 1,000-ship navy concept."
By this, Maslowski presumably means that SM-3 is a "truly global missile defense capability" as long as you have ships carrying it all over the globe. Raytheon admits that SM-3 isn't able to pick off proper three-stage intercontinental ballistic missiles (ICBMs) such as those deployed by Russia, China, or France. Or even, according to some sources, by North Korea and Iran in the reasonably-near future.
"The SM-3 Block IA provides increased capability to engage short to intermediate-range ballistic missiles," according to Raytheon, meaning that it could conceivably defend friendly nations or US taskforces from strikes by one or two-stage rockets in service today with North Korea, Iran, or (soon) India. SM-3 could do this provided there were Aegis-equipped warships in the right place, anyway, which is where the 1,000-ship navy comes in.
This concept, Theater Ballistic Missile Defence, is relatively achievable. Technologies such as SM-3 and the US Army's Patriot may soon develop to the point where they can fairly reliably take down slower, lower-flying ballistics in realistic numbers. The US will probably pass this kit on to its favoured allies like Israel and Japan, affording them some degree of safety from theatre-range weapons in the hands of their threatening regional neighbours. American forces could operate with impunity within the missile footprint of hostile lesser powers, too.
But major powers with ICBMs will still be able to menace the continental USA itself, and no functional defence yet exists. But the Pentagon's Missile Defense Agency is working on it, and so is Raytheon. The same Arizona factory which assembles the SM-3 is also building the "Exoatmospheric Kill Vehicle," which is intended to engage ICBMs above the atmosphere as part of the Ground-based Midcourse Defense Program. This is only one of the layered obstacles that enemy ICBMs of the future may have to penetrate in order to hit the US.
Reliable ICBM defences are still a long way off, however. But the possibility of their existence is an intriguing one. For instance, if one postulates a working American missile umbrella, it becomes much easier to imagine the UK choosing to dispense with its own deterrent weapons.
At the moment, those in favour of operationally-independent UK ICBMs argue that Brits can't expect the USA to respond to any nuclear attack on Blighty alone, because that might lead the aggressor nation to vapourise America as well. A US president, the reasoning goes, is unlikely to sacrifice American cities merely to avenge dead Brits. Thus, Britain needs its own nukes.
But if the Americans were safe from any attack, they'd probably feel able to nuke a country which had nuked the UK: and this could put off future nuclear aggressors from doing so. Thus, in a world where the USA has a working missile shield, the UK might not feel the need for its own atomic arms. Provided it was still a US ally, anyway.
On the other hand, there are other countries who would be upset. At the moment, Russia and China can feel safe from US invasion - they could always nuke America, so nobody would be likely to try. But once the Americans are safe from ICBMs, in theory they could send out a theatre-protected taskforce with impunity against whoever they choose, even if the object of their attentions was backed by Beijing or the Kremlin. The Russians or Chinese might even have to surrender to US invaders on pain of being unanswerably nuked, and America could get bogged down in a colossal, horrendous Asian counterinsurgency quagmire to its heart's content.
At least, the USA could do that sort of thing if all its troops weren't already tied down in Iraq or somewhere. Maybe the Russians and Chinese don't have that much to worry about after all. ®