Two tons of explosives packed in a fuel truck have shattered the security of US forces in Saudi Arabia and raised new concerns about the future of an ally Washington has long considered a stable bastion in the most volatile region of the world.
Reverberations from Tuesday's deadly explosion at an air base in a suburb of Dhahran could affect everything from US efforts to promote Arab-Israeli peace to the price of gas in America. The bombing's sad toll may also serve as a reminder to US voters of the dangers their troops face every day, from Bosnia to Bahrain.
"This is a tragic signaling of the end of the victory party that we've had since the Gulf war in the Middle East," says Shibley Telhami, a regional studies expert at Washington's Woodrow Wilson Institute.
If nothing else, the explosion puts the fight against terrorism back high on the US foreign-policy agenda. President Clinton is vowing to make terrorism a top subject at the summit of seven industrial nations that begins today in France.
At the time of writing no group had claimed responsibility for Tuesday's blast, which dug a crater 35 feet deep and 80 feet wide and was felt more than 50 miles away. The Pentagon put casualties at 19 Americans dead, and some 270 wounded. The official Saudi press agency said 149 Saudis were also hurt in the attack - and the Saudi government offered a $2.7 million reward for information leading to the arrest of the perpetrators.
Casualties could have been even higher if it had not been for security at the Dhahran site, said Pentagon officials. Concrete barriers prevented the truck from being driven into the Khobar Towers housing and office complex. The explosion took place outside a perimeter fence, yet still blew off the front half of an eight-story apartment building.
Last November, a smaller car bomb destroyed the headquarters of an American-run military training center in the Saudi capital of Riyadh. Taken together, the two bomb attacks call into question the safety of US personnel in a nation long thought more secure than most US Middle Eastern friends.
Dhahran is a nexus of United States activity in the Saudi kingdom, home to both American oil workers and military forces.
Yet US-based experts caution against jumping to the conclusion that the bombings are a pure anti-US campaign orchestrated by Iran, Iraq, or some other regional ally. They point out that the bombings have taken place in the context of a complicated local political situation.
Hand of Iran
Iran, say, may yet turn out to be involved. Tehran was "deeply implicated" in a recent attempted overthrow of the ruling family in the Gulf state of Bahrain, points out Robert Lieber, an expert on US Middle East policy at Georgetown University in Washington.
But four Saudi Muslim militants confessed to the Riyadh bombing, and were beheaded by the Saudi government in May. This week's attack could have been some sort of revenge for the executions. Furthermore, the local Shiite Muslim community has long carried clear-cut political and economic grievances against Saudi Arabia's Sunni Muslim theocracy.
"About 98 percent of the potential for doing this is domestic and homegrown," says Graham Fuller, a former CIA Saudi-Islamic expert now with the RAND Corp.
The apparent rise of an internal terrorist threat to the Saudi government comes at a time when its own leadership is in transition. Saudi King Fahd has been ill for months, and almost all power has reportedly passed to his half-brother, Prince Abdullah.
This change could have important implications for the US-Saudi strategic alliance. In the past Abdullah has placed greater emphasis on close relations with Arab allies than has Fahd, and he is close to Syrian leader Hafez Al Assad - a longtime roadblock to US Israeli-Arab peace efforts.
US officials say that the ascetic Abdullah is far from anti-Western, however, and that they believe he will not make drastic changes in his conservative nation's foreign policies.
That means a continued presence of 5,000 to 10,000 American military personnel, and continued US help in building up the internal Saudi security apparatus. Saudi Arabia and the US "share the belief that direct American involvement is vital to our national interest and theirs," says Richard Fairbanks, a former US ambassador and Middle East peace negotiator.
A question of oil
Oil, of course, remains a major US interest in the Gulf region. If anything, Saudi Arabia is more important to US energy security now than it was at the time of the Gulf war. Riyadh accounts for fully 11 percent of world oil production, and is the leading source of oil imports for the US, Japan, and many Western nations.
If internal unrest constricts Saudi oil production, it could increase gas prices in the US. Indeed, world oil prices jumped 20 cents a barrel on Wednesday in reaction to the Dhahran attack.
Problems in Saudi Arabia could also make it more difficult for the US to rally Arab nations to continue peace efforts with Israel - and to continue to isolate Iran and Iraq. "Clearly, we have to play a lot more attention than we have to public opinion and societal forces within the Gulf states," concludes Shibley Telhami of the Wilson Institute.
* Staff writers Robert Marquand, Jonathan S. Landay, and Faye Bowers contributed to this report.