Friday's gruesome beheading of Lockheed-Martin helicopter engineer Paul Johnson Jr., the first such case in Saudi Arabia, shows the urgent need for U.S. officials to keep pressure on the Saudis to crack down on al-Qaida and their funding sources.

U.S. contract work in the Middle East has become even more high-risk, and terrorists have shifted tactics to make it all the more so.

Secretary of State Colin Powell denounced the killers. "If anything," he said, "it will cause us - I'm quite confident, it will cause our Saudi colleagues - to redouble our efforts to go after terrorists wherever they are, wherever they are trying to hide and to go after those who support this kind of terrorist activity."

The militants who claimed credit Friday for slaughtering Johnson used U.S. prison abuse as an excuse, and claimed killing an innocent civilian was somehow sanctioned by God. In their statement, they called Johnson an infidel: "This is God's voice rising in anger at the treatment of Muslims in Abu Ghraib, al-Hair (prison), Guantanamo, Ruwais (Saudi prison) and others."

The same day, senior Saudi cleric Sheikh Saleh bin Abdullah al-Humaid, in a sermon at Mecca's Grand Mosque, denounced hostage-taking and murder as grave sins under Islam.

U.S. prosecutions of contractors accused of abusing detainees won't sway terrorists bent on unseating legitimate governments and seizing power for themselves. Thursday, a federal grand jury in North Carolina indicted David A. Passaro, a former Army Ranger and contract interrogator for the CIA in Afghanistan. Passaro is charged with brutally beating detainee Abdul Wali, who died shortly after questioning.

Since 2000, Army policy prohibited use of contractors to gather intelligence, although it allows for exceptions. That policy should not be skirted. It needs to be strictly enforced, and treatment of detainees kept humane. Terrorists used U.S. prison abuse as an excuse to execute other U.S. civilians in the Middle East lately - Kenneth Scroggs, Robert Jacobs and Nicholas Berg, who also was beheaded. We cannot negotiate with terrorists. Rather we need to strengthen Middle East alliances to hunt down the killers.