Kuwait, which was invaded by Iraq in 1990, is particularly vulnerable. RAF Tornados are based in the Gulf state and are flying against Iraqi targets.
"Iraqi soldiers save yourselves! Stay in your positions! Do not head south!" one of the papers warned in Arabic. The air strikes were aimed at "only units who support the Baghdad regime," it said.
Though there were some attacks on the regular army, most of the cruise missile strikes were aimed at the Republican Guard, the elite military formations loyal to Saddam, and then principally at command headquarters, divisional and corps commanders.
The leaflets harked back to the Gulf War. "This was Saddam's 'mother of all battles'," said one of the leaflets, emblazoned with a picture of destroyed Iraqi tanks. "If you threaten Kuwait, the coalition forces will destroy you again."
"It told those down south to stay put," said General Hugh Shelton, chairman of the US military Joint Chiefs of Staff.
The south of the country is also where the Shiite opposition is based. It rose up against the regime in 1991, encouraged by President George Bush, and was then crushed. The leader of the Iraqi National Congress, one of the main opposition groupings, has suggested that he wants to establish a "free zone" in the south. The US has said that it would consider funding the opposition.
The US is sending more ground forces to reinforce the region, partly with a view towards deterring Iraqi retaliation. An additional 2,000 Army troops are bound for Kuwait where they will join 3,000 US soldiers already on exercise there. The USS Carl Vinson, an aircraft carrier, and its carrier battle force have also arrived in the Gulf. Gen Shelton said that the new forces would provide commanders "with additional flexibility in the region."
Adding to the frisson over Iraq's southern border, there were reports that Saudi Arabia had moved its forces closer to the frontier. This was later strenuously denied by the Saudi authorities, apparently wary of sparking a crisis.Reuse content