the biggest problem the U.S forces are facing besides the EFP IED supplied by iran and syria is the new warheads they are putting on the RPG-7 and the deployment of the RPG-29. also Metis-M and Kornet are being used in larger numbers but this is not being annouced by the DoD. Some cases of Metis-M hits are being reported as EFP IED hits.
I dont see the PRC aiding the insurgancy in any way. no reports of PRC weapons systems in Iraq.
I'd like to see some proof of this. Certainly it is possible, and your probably right that the insurgents are using more effective RPGs. However I haven't heard anything about the use of Kornets and Metis-Ms. Since Kornets were responsible for knocking out Merkavas in Lebabnon, it would stand to reason that they are capable of taking out M-1 Abrams as well. And this would be consistent with your claim that these ATGM hits are being reported as EFPs because if have heard reports of Abrams being taken out by EFP IEDs, which seems unlikely to me.
The thing that bothers me most is how would the Pentagon keep it secret? I suppose the answer to that question is dependant on the frequency of the use of these weapons; if they are used somewhat frequently then word of their exsistance would be more widespread. If they have only been used in a few instances then their use could be covered up.
Either way it is bad for US troops. And if this is true it is the most convincing evidence yet of direct Iranian support of insurgent groups in Iraq.