Guns per 100 residents: 34.2
The law: Iraq's culture of gun ownership was well-established before the U.S. invasion of 2003. (So much for the argument that a well-armed populace is a defense against tyranny.) These weapons -- combined with those commandeered from the disbanded Iraqi Army -- were to prove far more deadly to U.S. troops in the coming years than the chemical or biological attacks that many feared.
Under laws instituted by the U.S.-backed Iraqi government in 2003, Iraqis were still allowed to keep guns up to 7.62 mm -- the caliber of an AK-47 -- as long as they were registered. A license is required to carry any gun in public. But even these relatively liberal laws have proved difficult to enforce. During an amnesty campaign to encourage Iraqis to turn in their guns at police stations before the new laws went into effect in 2003, not a single weapon was brought in to most locations, according to the BBC.
In fact, the main impact of the U.S. invasion on Iraq's flourishing black-market arms trade has been the creation of sectarian militias that helped drive up prices for firearms.