As the Pentagon is accused by US auditors of losing track of 190,000 AK-47 assault rifles and pistols given to the Iraqi security forces, the BBC's Nick Childs considers what this means for US strategy.
This report is particularly embarrassing for the Pentagon, in part because the plan to train and equip new Iraqi security forces has been so central to its strategy in the country.
Fears are rife of guns falling into the wrong hands
And, while it has been alleged before that weapons bound for the Iraqis have gone missing, the numbers in this report are striking.
The report comes from the Government Accountability Office (GAO) which is an independent US government agency that is essentially the watchdog and investigative arm for the US Congress.
The GAO says that, of some 185,000 assault rifles and 170,000 pistols that the Pentagon says it supplied to the Iraqi security forces, it can account for less than half: there is a discrepancy of 110,000 in the case of AK-47s, and 80,000 pistols.
The gaps in the figures for body armour and helmets are even bigger - only 80,000 out of a total of 215,000 sets of body armour accounted for, and only 25,000 out of 140,000 helmets.
The report does not say it knows what has happened to the weapons - only that there are gaping holes in the records.
The focus of the report is on perceived Pentagon failures but, by implication, it also raises questions about the capabilities and reliability of the Iraqi security forces. There is the fear, again long suspected, that many of the missing weapons have found their way into the hands of insurgents.
There remain question marks over the reliability of elements of the Iraqi security forces, especially the police.
PENTAGON'S MISSING HARDWARE
AK-47 rifles: 110,000
Body armour pieces: 135,000
Of course, the Pentagon was under huge pressure from early on to try to achieve quick results in its programme to train and equip the Iraqi forces.
These faltered on more than one occasion and tracking what happened to the weaponry may not have been the top priority for limited resources.
In barely more than a month now, the top US military commander in Iraq, Gen David Petraeus, and the US ambassador, Ryan Crocker, are meant to give their assessment of how the latest US strategy for the country is working.
This latest report may well provide more ammunition for the sceptics.
Gen Petraeus arrived in Iraq earlier this year with a huge reputation, not least because he was credited with turning round the training programme on his previous assignment to the country.
But he was also in charge of it for much of the time covered by this investigation - and that could damage his credibility.
Whether the Iraqi security forces are up to the job, and whether they have enough of the right equipment, remain keys issues for the way ahead in Iraq.
And the Pentagon has, according to the GAO report, asked for another $2bn for new equipment for those forces.
The Pentagon says it accepts key recommendations in the report on improving records and accountability, and that steps have been taken.
But the report says that, as of last month, the Pentagon had not specified what the accounting procedures were.