If the press reported it correctly, weapons stolen from Iraq's army were a big enabling factor for the ISIS fast growth. They would invade a new region and get for free a big enough supply for invading the next place.

Venezuela, by its turn, is mostly Brazil and Argentina's fault. The US gave some financing to the current government, but it's a rounding error overall. The Brazilian government even helped organizing their dictatorship at the time it was trying to do the same here.