To take the last item first, there is no evidence that the "explosively formed penetrators" (EFPs) they refer to have been manufactured exclusively in Iran or even that only Iran is capable of making these. There is much evidence that Iraqis are perfectly capable of manufacturing EFPs in local machine shops. Second, Iraq fought a very lengthy war with Iran from 1980 to 1988. The skills of "how to fire rockets and mortars [and to] fight as snipers" are simply not difficult to obtain there. Iraq has millions of veterans of that war that have been more than capable of passing on this kind of knowledge.
The Mideast is a heavily militarized place that has seen much fighting over the last several decades. There is no reason that jihadists can't "hit the ground running," i.e., arrive in Iraq fully competent, equipped and ready to start fighting Americans. There is no reason to think they have to make a stop-off in Iran first. As Juan Cole points out about the weapons themselves:
After all, Iran has a well developed criminal black market in arms (Ronald Reagan once got involved in it). So the presence of Iran-made weapons proves nothing about Iranian government intentions. The ayatollahs in Tehran have been openly siding with the al-Maliki government against the Mahdi Army militia.
The really important point to make about this article is that every single, solitary scrap of information included in it comes second-hand from anonymous American "officials." Some also makes its way from Iraqi officials, who were in turn briefed and shown "captured Iranian equipment" by, you guessed it, anonymous American "officials." Absolutely nothing, none of the interrogated prisoners, none of the "captured Iranian equipment," has been personally viewed by reporters or by anyone who might provide anything approaching an objective, non-deeply-compromised point of view.
This article ratchets up tension still further. Two NYT Public Editors have been critical of reporter Michael Gordon's work in the past, Byron Calame:
The problem with Gordon's work, however, is far more extensive than just one article. He collaborated with Judith Miller on many Saddam-Hussein-has-WMD pieces that served as justification for war with Iraq and as we've seen in today's article (May 5th), these problems with uncritically repeating administration claims have hardly stopped. Public Editor Clark Hoyt also criticizes Gordon and Gordon's style of reporting Administration claims:
And in using the language of the administration, the newspaper has also failed at times to distinguish between Al Qaeda, the group that attacked the United States on Sept. 11, and Al Qaeda in Mesopotamia, an Iraqi group that didn't even exist until after the American invasion.
As to claims about Iranian involvement in Iraq being presented by Iraqis as credible, believable sources the Christian Science Monitor reports that Iraqis are feeling squeezed between America and Iran."We do not want to start a conflict with Iran," says Iraqi spokesman Ali al-Dabbagh. "We need our own government documentation of this interference, not from the Americans, not from the media."
He suggested Sunday that Iraq had no "hard evidence" of Iran's involvement or of the 2008 markings on seized weaponry, and that a top-level committee would be formed to investigate.
Very interestingly, this statement appears nowhere in the NY Times article cited above.