From The Economist.
The conflict between America and Iran intensifies in Iraq
For months young Iraqi protesters trying to reach the Green Zone, the government enclave in Baghdad, were met with bullets and tear-gas canisters, the latter often fired at their heads.
But on December 31st hundreds of militiamen were allowed to enter unmolested. The men, affiliated to Kataib Hizbullah, an Iranian-backed Shia paramilitary group, tried to storm the American embassy.
They threw petrol bombs over the walls and broke into a reception area where security personnel would normally screen visitors. Iraqi police largely stood by for hours; it was not until nightfall that the Counter Terrorism Service (CTS), an elite unit, sent men to secure the embassy.
They did not have orders to evict the rioters, who made plans to camp outside. As night fell, American Apache helicopters could be seen flying overhead, dropping flares.