Saddam Hussein deserves no one’s pity. But as anyone who has seen the graphic cellphone video of his hanging can testify, his execution bore little resemblance to dispassionate, state-administered justice. The condemned dictator appeared to have been delivered from United States military custody into the hands of a Shiite lynch mob.

For the Bush administration, which insists it went to war in Iraq to implant democracy and justice, those globally viewed images were a shaming embarrassment. Unfortunately, all Americans will be blamed, while the Iraqi people are now likely to suffer still more. What should have been a symbolic passage out of Iraq’s darkest era will instead fuel a grim new era of spiraling sectarian vengeance.

The ugly episode shows why Prime Minister Nuri Kamal al-Maliki is never likely to produce the national unity government that Washington keeps demanding and that Iraq so desperately needs.

Mr. Maliki is now scrambling to extricate himself from the public relations disaster. Yesterday, his office announced the arrest of a guard who allegedly took the unauthorized video. But the fundamental blame belongs to Mr. Maliki, who personally orchestrated the timing and circumstances of last Saturday’s execution.