In what the White House proudly describes as his “bluntest remarks” yet on whether the United States and Russia can come to agreement on amending the 1972 Anti-Ballistic Missile Treaty to accommodate a missile defense shield it expressly prohibits, President Bush now says he will withdraw from the treaty “at a time convenient to America.” Blunt, yes; clear, no.

The lack of clarity fuzzed up the very same sentence – this unilateral decision would come only after consulting with European allies and Russia, truly a unique view of consultation. Like the incoming warheads the shield would defeat, this administration continues to set up a moving target for those seeking consensus.

The rationale for scrapping the ABM Treaty is that it is an impediment to the next phase of testing for the shield. President Bush met with Russian President Vladimir Putin last month over that issue, followed by a parade of high-ranking arms-control officials going to Moscow to press the point. Moscow responded by signaling that it is open to limited amendments to allow such testing. The United States now responds by saying the treaty cannot be amended; it must instead be scrapped. And, adds the president, “on our timetable” for a decision yet to be made and without a firm timeline.

But the cause of the greatest fuzziness continues to be the disconnect between the stated purpose of the shield – to protect America and perhaps the world from attack by rogue nations or terrorists – and the developing technology – incredibly expensive stuff that seems specifically designed not to do that very thing. If nothing else, this scenario of ill-defined purposes and results that defy measurement is highly convenient for American defense contractors.

There are two glaring discrepancies that must be resolved before a treaty that has worked for 28 years is tossed aside and before Congress approved the president’s request for another $18.5 billion for this project. The first has to do with what the shield is supposed to stop.

The missiles developed by the United States and the Soviet Union during the Cold War were extremely accurate – the Soviets, it is said, could have aimed a warhead at the Washington Monument and probably done no worse than splashing down in the Reflecting Pool. The so-called rogue nations are not simultaneously exploring space or developing missiles for tactical use on the battlefield; they have no need for such an expensive and advanced nicety as accuracy. Iraq could aim at the Washington Monument, hit a Maryland suburb and accomplish its mission of causing enormous misery.

The problem is that warheads delivered by these two grades of missiles present vastly different profiles to tracking equipment. Accurate warheads come in a tight, football-like spiral – they are easily detected; it is dummy warheads of this type that have been used in the modestly successful tests done so far. Inaccurate warheads tumble wildly end-over-end; they can look to tracking equipment like anything from a twinkling star to a migrating Canada goose. Antimissile experts, both in the Pentagon and out, agree that the tumbling warhead problem is daunting and that even the most rudimentary testing of interceptors could be several years away.

The second has to do with a threat no shield will ever stop, but one that security experts the world over agree is possibly the most serious – nuclear devices hand-delivered by terrorists, such as by suitcase bomb. The technology to build such bombs is widely known; the only real impediment is the difficulty of obtaining the necessary weapons-grade plutonium.

It only takes a few pounds of this plutonium to make a bomb; together, the United States and Russia have some 260 tons in storage. It is estimated that half of Russia’s plutonium, about 80 tons, is insecurely stored and increasingly tempting to terrorists.

The United States and Russia worked out a plan last year to begin disposal of the Russian plutonium, either by burning it in nuclear reactors or by encasing and burying it. This entire project would cost about $9 billion, including a substantial upgrade in security at Russian storage sites. Although several European nations have offered to contribute, the Bush administration is backing away from the agreement, saying it prefers to wait until cheaper disposal technology is developed, although no such technology is even on the horizon. Blunt, perhaps; pointless, absolutely.