Just don’t hand them over to the Iraqi Army.
Regarding the 2,000 or whatever number of Humvees that ISIS reportedly captured from the Iraqis. An officer friend of mine, who had 4 tours in Iraq between 2003 and 2011, he said there were easily 1-2,000 Humvee hulks left in Iraq by the US Army because they were just so much junk or the source for an occassional spare part when we pulled out in 2011. those Humvees were written off due to IEDs, other battle damage or wrecks.