A Ring Around Iran
By THEODORE POSTOL Published: July 11, 2007
PRESIDENT VLADIMIR PUTIN of Russia has made an offer that President Bush cannot refuse — not if Mr. Bush truly wants substantive international cooperation on missile defense. Last month, Mr. Putin offered to give America access to data from a Russian early-warning radar unit in Azerbaijan that can observe the launching and flight of any long-range ballistic missiles from Iran. The offer was part of Mr. Putin’s effort to keep the United States from setting up its own missile-defense system in Poland and the Czech Republic.
The Azerbaijan proposal makes sense in two ways: it could end the diplomatic tussle over the Eastern Europe plan, and it could also be a more effective check on Iran. This is because the technical features of the Russian radar complement those of American missile-defense radar systems, like the one now being set up in Alaska. (Let’s leave aside, for the moment, the question of whether missile defense will ever be very effective, something I’m quite skeptical about.)
If we are going to pursue missile defense, we should not only accept the data-sharing offer but also place American defense radars and other technology in Azerbaijan, or possibly in nearby Turkey: working together could substantially increase the chances of making a missile defense against Iran more effective.
Here’s the technical explanation. The Russian radar uses low-frequency radio signals to search for distant ballistic missile warheads. The wavelengths of these radio signals are close to the dimensions of the warheads, so you get very strong oscillations of the electromagnetic field and a huge reflection of the signal back to the radar where it can be detected.
By contrast, the favored American missile-defense radar operates at frequencies 70 times higher. The advantage of this is that you get 70 times better radar resolution, and thus a far clearer picture of the object. Clarity is important when it comes to figuring out exactly what sort of a missile you are dealing with and distinguishing an actual warhead from debris. However, at such high frequencies the amount of radio energy that is reflected back to the radar is very small, typically one one-hundredth or less of that received when using the lower frequencies of the Russian radar.
What all this means is that the Russian radar can quickly and effectively search the sky for missiles, but has little ability to determine exactly what it has found. The American radar may take longer to find the object, but can carefully observe its structural details. It should be obvious that when you use two