A federal appeals court on Thursday said that the government can legally order communications companies to help gather intelligence on people "reasonably believed" to be outside the United States -- even Americans -- without obtaining a warrant. 

The Foreign Intelligence Surveillance Court of Review, in its second opinion ever made public, gives a big boost to the Bush administration's warrant-less wiretapping efforts. 

"Requiring a warrant would (likely) hinder the government's ability to collect time-sensitive information and, thus, would impede the vital national security interests that are at stake," the 29-page ruling said. 

The decision stems from a 2007 amendment to the Foreign Intelligence Surveillance Act, the Protect America Act, which gave the U.S. government the authority to demand that U.S. telephone companies and other communications companies assist in warrant-less surveillance of certain customers. 

When the government ordered an unnamed company to do so in 2007, the company challenged the order's legality with the Foreign Intelligence Surveillance Court, which oversees intelligence-gathering efforts overseas. 

"The government's efforts did not impress the (company)," the ruling released Thursday said. 

Specifically, the company argued that the order violated the Constitution's Fourth Amendment, which protects Americans against unreasonable searches and seizures. But the court, composed of 11 federal judges from around the country, said the order was legal and directed the company to comply. 

Facing contempt of court, the company subsequently complied with the government's order. But the company appealed the matter to the Foreign Intelligence Surveillance Court of Review, a panel of three judges from the larger court. In August 2008, they upheld the legality of the government's order, though the ruling was classified until Thursday. 

"That dog won't hunt," the ruling said of the company's legal argument. 

The three-judge panel, though, clarified that, "This ruling does not grant the government carte blanche." 

The ruling said the government still has to follow the letter of the law, particularly the Fourth Amendment, and the attorney general has to find "probable cause" after reviewing each case. 

"Where the government has instituted several layers of serviceable safeguards ... its efforts to protect national security should not be frustrated by the courts," the ruling said. 

The Justice Department said it is "pleased" with the ruling. Even though the amendment at issue expired in February 2008 -- replaced by newer amendments to the Foreign Intelligence Surveillance Act -- one Justice Department official said the ruling could impact other surveillance-related rulings in the future. 

"This is a very significant decision," said Sen. Orrin Hatch, R-Utah, at the confirmation hearing for Attorney General-nominee Eric Holder

The last opinion made public from the Foreign Intelligence Surveillance Court was released in 2002. It criticized FBI and Justice Department officials for supplying erroneous information to the court in applications for warrants and wiretaps. It was the first time since the court was established in 1978 that an appeal had been made. 

Asked whether any appeals had been made to the court between 2002 and the ruling released Thursday, a Justice Department spokesman said, "No comment."