Here's the statement from Homeland Security Secretary Michael Chertoff:
The Department of Homeland Security is taking immediate steps to increase security measures in the aviation sector in coordination with heightened security precautions in the United Kingdom. Over the last few hours, British authorities have arrested a significant number of extremists engaged in a substantial plot to destroy multiple passenger aircraft flying from the United Kingdom to the United States.
Currently, there is no indication, however, of plotting within the United States. We believe that these arrests have significantly disrupted the threat, but we cannot be sure that the threat has been entirely eliminated or the plot completely thwarted.
For that reason, the United States government has raised the nation's threat level to Severe, or Red, for commercial flights originating in the United Kingdom bound for the United States. This adjustment reflects the Critical, or highest, alert level that has been implemented in the United Kingdom.
To defend further against any remaining threat from this plot, we will also raise the threat level to High, or Orange, for all commercial aviation operating in or destined for the United States. Consistent with these higher threat levels, the Transportation Security Administration is coordinating with federal partners, airport authorities and commercial airlines on expanding the intensity of existing security requirements.
Due to the nature of the threat revealed by this investigation, we are prohibiting any liquids, including beverages, hair gels, and lotions from being carried on the airplane. This determination will be constantly evaluated and updated when circumstances warrant. These changes will take effect at 4 a.m. local time across the country. Travelers should also anticipate additional security measures within the airport and at screening checkpoints.
These measures will continue to assure that our aviation system remains safe and secure. Travelers should go about their plans confidently, while maintaining vigilance in their surroundings and exercising patience with screening and security officials.
The United States and the United Kingdom are fully united and resolute in this effort and in our ongoing efforts to secure our respective homelands.
The conditioning has worked. Ivan Pavlov would be proud.