The story: In a bid to stem widespread armed violence, Iraq’s Ministry of Interior is pushing ahead with a program to encourage Iraqis to register or sell privately-owned weapons. In the latest phase of the four-year program, the government is now offering a buyback mechanism for arms such as rocket-propelled grenades (RPGs) and mortars.

Critics have charged that the campaign is destined to fall short of its objectives, claiming that most unregistered weapons are...