U.S. military and intelligence officials tell ABC News that they have caught shipments of deadly new bombs at the Iran-Iraq border.

What the United States says links them to Iran are tell-tale manufacturing signatures -- certain types of machine-shop welds and material indicating they are built by the same bomb factory.

"I think the evidence is strong that the Iranian government is making these IEDs, and the Iranian government is sending them across the border and they are killing U.S. troops once they get there," says Richard Clarke, former White House counterterrorism chief and an ABC News consultant. "I think it's very hard to escape the conclusion that, in all probability, the Iranian government is knowingly killing U.S. troops."

What is wrong with this picture? These bombs were allegedly caught "at the Iran-Iraq border." If that were true, why on earth would you need to resort to obscure "manufacturing signatures" of "machine-shop welds" to link them to Iran? They were captured at the Iran border! Or so "they" say.

And that, of course, is the second rat. Who is "they"? If IEDs were really captured at the Iran-Iraq border, surely that is a simple fact, known not only to the Americans and the Iraqis but also to the smugglers and resistance fighters who are getting their weapons in this way. There may be some secret intelligence aspects to how they found out these alleged weapons were coming across the border, but surely there can't be any about the fact that they were intercepted (if indeed, it is a fact). So why the secrecy? Why is this story being told "exclusively" to ABC News by unnamed U.S. military and intelligence officials, rather than being announced from the White House by George Bush or Scott McClellan? Why isn't Donald Rumsfeld on TV, holding up one of these IEDs and denouncing Iran? Something is just not right about this. Not to mention the fact that even the "usual suspects" (other networks, major newspapers) don't seem to have picked up this story.

As with many things, context matters. And what is the context? The U.S. wants an excuse to take military action against Iran, for a variety of reasons. Their "sky is falling, Iran is building nuclear weapons" story has some traction, but not enough, and there's still the possibility that Iran and Russia might reach some agreement which completely cuts the legs out from under the U.S. argument. So what better time than to come up with a second "reason" for war, that being that Iran is already effectively declared war against the U.S.?

Update: Lending credence to my analysis, Donald Rumsfeld held a press conference today. He didn't bring this subject up at all, but was indirectly asked about it (but his partner in crime, Gen. Peter Pace, answered):

Q Are you seeing weapons, Iranian-backed weapons, coming into Iraq, sir? Are U.S. forces engaging these Iranian elements?

GEN. PACE: There have been some IEDs and some weapons that we believe are traceable back to Iran.

Q Well, there was one shipment that was -- (off mike) -- last year that you have talked about. Are you seeing more recent shipments of Iranian -- of weapons you believe manufactured in Iran and shipped across the border?

GEN. PACE: The most recent reports have to do with individuals crossing the border into Iraq.

So from ABC's claim of "shipments of deadly new bombs [caught] at the Iran-Iraq border," we're down to "some" weapons found last year that we "believe" are "traceable back to Iran" (i.e., that were clearly not intercepted at the border).