* Justices split 5-4 on wiretap law
* Loss for human rights groups, journalists (Adds reaction)
By Lawrence Hurley and Jonathan Stempel
WASHINGTON, Feb 26 (Reuters) - U.S.-based journalists, lawyers and human rights groups cannot challenge a federal law that allows surveillance of some international communications, the Supreme Court ruled on Tuesday in a case touching on government efforts to fight terrorism.
Split 5-4 on ideological lines, with conservatives backing the government and the liberal wing in the minority, the country's highest court said none of the three categories, including human rights groups Amnesty International and Human Rights Watch, have legal standing to sue because they could not show they had suffered any injury.
The law in question was the 2008 amendment to the Foreign Intelligence Surveillance Act (FISA) that authorized mass surveillance by the U.S. government, without identifying specific targets, for the purpose of monitoring foreigners outside the country and gathering intelligence.
President George W. Bush authorized warrantless wiretaps after the Sept. 11, 2001, attacks to find people with ties to the al Qaeda network and other groups. He ended that program in 2007, but Congress the next year reinstated parts of it.
The Obama administration argued that the challengers did not have standing, a position the court's majority endorsed. The Justice Department declined to comment on the ruling.
Jameel Jaffer, the American Civil Liberties Union lawyer who argued the case for the challengers, called the ruling "disturbing."
"This ruling insulates the statute from meaningful judicial review and leaves Americans' privacy rights to the mercy of the political branches," he said in a statement.
Since the Sept. 11 attacks, the Supreme Court has been reluctant to intervene in White House affairs governing national security and intelligence-gathering procedures, and the government has said it needs to be flexible in surveillance.
But the challengers said the amendment unreasonably added to their burdens by forcing them to stop communicating by phone and email with sources and clients, including in such places as Afghanistan or Guantanamo Bay, Cuba, and instead meet in person.
They also said it could subject millions of people to monitoring without a warrant, violating the protection against illegal searches and seizures under the Fourth Amendment of the U.S. Constitution.
'HIGHLY SPECULATIVE FEAR'
In Tuesday's ruling, Justice Samuel Alito wrote on behalf of the majority that the challengers' argument was based on a "highly speculative fear" that the government would target their communications and not choose other means to carry out surveillance if it was required.
The law states that U.S.-based people should not be targeted and the various individuals and groups that filed suit had not shown any evidence that they had been, Alito said.
Likewise, the law's opponents had no evidence that the non-U.S. people they are communicating with have been targeted either, he added.
"We decline to abandon our usual reluctance to endorse standing theories that rest on speculation about the decisions of independent actors," Alito wrote.
Justice Stephen Breyer wrote a dissenting opinion in which he took issue with Alito's conclusion that the likelihood of harm was purely speculative.
"Indeed, it is as likely to take place as are most future events that commonsense inference and ordinary knowledge of human nature tell us will happen," Breyer wrote.
In the past, the court has embraced that wider view of what constitutes standing, he added.
Breyer said there is a "very high likelihood" that the government would cite the law when intercepting communications of the type at issue in the case.
Peter Godwin, president of the PEN American Center, one of the human rights groups that brought the challenge, said the decision was a "Kafkaesque holding that puts writers, journalists, human rights workers on notice that the U.S. government can look over their shoulders anywhere in the world."
Adopted in 1978, FISA required the government to submit a surveillance application to a special court for each person outside the country it was targeting.
The case is Clapper et al v. Amnesty International et al, U.S. Supreme Court, No. 11-1025. (Reporting by Jonathan Stempel and Lawrence Hurley; Editing by Howard Goller, Eric Beech and Mohammad Zargham)