The Pentagon prepares for a misille attack from Iran

A Ghadr 1 class Shahab 3 long-range missile is prepared for launch during a test from an unknown location in central Iran

Fake "North Korean" missiles have been hurtling over the Pacific toward the U.S. for years, providing test fodder for the Pentagon's missile-defense systems. But next month, the fake enemy missiles flying over the same ocean are going to be "Iranian." The timing of the test, however, has nothing to do with a missile test-fired by Iran on Tuesday. That was a medium-range Sajjil-2 missile capable of targeting Israel or U.S. bases in the Persian Gulf. Next month's U.S. interceptor test will, instead, be aimed at the as-yet-hypothetical threat of an Iranian intercontinental ballistic missile (ICBM), even though such a threat has been deemed by the Obama Administration to be unlikely in the immediate future.

The Administration announced earlier this year that the long-range Iranian threat isn't advancing as quickly as once feared. Recent U.S. intelligence assessments have concluded that "the threat of a potential Iranian ICBM had been slower to develop than previously estimated," Ellen Tauscher, the State Department's arms-control chief, told Congress. Some intelligence estimates say an Iranian ICBM might not happen until 2020. That assessment prompted the President, with Pentagon support, to scrap a land-based interceptor system based in Poland and the Czech Republic and instead to deploy ships capable of shooting down the short- and mid-range Iranian missiles that U.S. intelligence believes pose a more imminent threat — like the sort of missile test-fired by Iran this week.

Next month's missile test not only will be aimed at a threat deemed less than urgent but will also involve tougher technical challenges. Destroying a "North Korean" missile involves hitting it as it zooms from left to right across an interceptor's field of view, but the locations of the "Iranian" missile and the U.S. interceptors require more of a head-on collision. That means the closing speed between the two projectiles will be faster than in previous tests: close to 18,000 m.p.h., compared with 15,000 m.p.h. in prior exercises.

That reduced shoot-down window means the interceptor will have to work more quickly to do its job. "Whenever we have a situation where we're taking on a missile more head-on than from the side, that increases the challenges," Army Lieut. General Patrick O'Reilly, the U.S. missile-defense chief, told a defense gathering sponsored by Reuters on Monday. The test is expected to send an interceptor missile from Vandenberg Air Force Base in California at a fake Iranian missile, fired from the Marshall Islands.

The U.S. currently has 23 ground-based interceptors based in Alaska and California, and they could be used against missiles launched — for real — from either North Korea or Iran. "They can go both ways," O'Reilly told Congress in October. "If you look at the earth from the North Pole, you'll see that the closest part of the U.S. to Iran is Alaska." He added that the U.S. has other ways of destroying such weapons, including attacking them during the several days it takes to ready them for launch. "All ICBMs right now associated with Iran and North Korea are pad-launched," added General James Cartwright, Vice Chairman of the Joint Chiefs, at the same session. "They're very visible, they're up above the ground, and you can go after them before launch if you so desire. We're not advocating pre-emptive, but it is a physical capability that we possess."

It may, of course, make sense for the U.S. to hedge its bets on what it knows about Iran. Two years ago, the U.S. intelligence community declared that Iran had, in 2003, halted its secret push to build nuclear weapons. But last weekend a document, purportedly from inside Tehran's nuclear program, surfaced in a London newspaper suggesting that Iran has been busy developing the sophisticated devices necessary to trigger a nuclear explosion. Some intelligence officials believe that the undated document was written in 2007 — the same year U.S. intelligence said Iran had frozen its weapons program. Then again, neither the U.S. nor other Western intelligence agencies are able to verify the document's authenticity.

Obama Shelves U.S. Missile Shield: The Winners and Losers

President Obama's decision to shelve plans to station U.S. missile defenses in Poland and the Czech Republic is being portrayed as a pragmatic response to the threat of Iranian nuclear missiles. In confirming the move on Thursday, Sept. 16, Obama said the U.S. wants to focus instead on deploying "technologies that are proven and cost-effective and that counter the current threat" — that is, Iran's medium-range missiles, rather than any intercontinental ballistic missiles Iran could possibly develop.

But if the move raises concerns in Tehran, it's not because of any impact it will have on Iran's missile capability, but rather because the decision represents an enticement to Moscow to support new U.S. sanctions against Iran. At the same time, Russian officials must be smiling wryly at Obama's explanation that the plan was changed because of revised intelligence estimates of Iran's missile capability — since Moscow had never taken seriously the U.S. explanation that the shield was designed to protect against an Iranian threat. (An interceptor system targeting Iranian missiles would be more appropriately stationed in Jordan than in Poland, after all, and Moscow's vehement opposition to the planned deployment on its doorstep was based on fears that it actually was aimed at weakening Russia's own nuclear deterrent, because the system would be able to intercept Russia's missiles in the so-called boost stage.) Meanwhile, Obama's decision will surely raise alarms in the corridors of power in Ukraine, Georgia and other NATO-inclined countries in the former Soviet bloc, who saw the battle over the missile shield as a litmus test of Obama's willingness to stand up to Russia's efforts to re-establish its hegemony in its post–World War II sphere of influence.

Russian President Dmitri Medvedev and Prime Minister Vladimir Putin made it clear from the outset of the Obama Administration that any effort to "reset" U.S.-Russian relations would require that Washington do more to accommodate Russian concerns — first and foremost, its opposition to the missile shield and to NATO's expansion into former Soviet-bloc countries. Soon after taking office, Obama reportedly wrote a private letter to Medvedev suggesting that the missile shield would become unnecessary were Russia to help the U.S. prevent Iran from developing into a nuclear threat. The Russians also made the missile shield a central issue in negotiations with Washington over a new arms-control deal to replace the Strategic Arms Reduction Treaty. That treaty expires in December, and Obama has made putting a new treaty in place by then a priority of his Russia policy.

But the key nuclear-proliferation concern facing the Administration is Iran, which Western powers suspect is developing a capacity to build nuclear weapons under the cover of its civilian atomic-energy program. Although a new round of talks between Iran and the main international players has been scheduled for Oct. 1, the Administration is not anticipating a diplomatic breakthrough and is at the same time seeking support for new sanctions aimed at pressing Iran to cease uranium enrichment. Russia just last week reiterated that it opposes new sanctions.

Given the link drawn by Obama, soon after he took office, between Russian cooperation on Iran and the missile-defense plan, it's hard not to read the shelving of the missile shield as at least partly a move to enlist Russian support on Iran. It's not at all certain, however, that such support will be forthcoming. Moscow does not believe Iran is currently pursuing nuclear weapons, and its adversarial relationship with Washington will be maintained as long as the likes of Ukraine and Georgia are being considered for NATO membership. Critics in Washington are already accusing Obama of giving Moscow something for nothing.

Even more alarmed than Washington hawks are U.S. allies in former Soviet-controlled territories. Already, the limits of what former Soviet-satellite states can expect from the West was cruelly demonstrated last year, when the U.S. was unable to do anything to prevent Russian tanks from rolling into Georgia to punish that country's military for attacking South Ossetia. The missile-shield decision will confirm fears that Washington's power to roll back Russian influence in the region is waning.

Still, giving up the protection offered by the missile shield is not particularly difficult for the U.S. — for the simple reason that the shield doesn't offer any significant protection. The system that would have been deployed in Poland and the Czech Republic was in every sense a work in progress whose testing had not yet proved any real-world capacity to deal with a hostile missile threat. In that sense, the missile "shield" was every bit as hypothetical as the Iranian missile threat against which it was ostensibly deployed.