THE HAGUE (Reuters) - Prosecutors at the International Criminal Court will investigate whether war crimes were committed in Afghanistan by the Taliban, Afghan military and U.S. forces after an appeals panel said on Thursday the “truth-seeking” inquiry should go ahead.

The ICC decision, which came days after the United States agreed to pull its troops from the long-running conflict, opens the way for prosecutors to launch a full investigation, despite U.S. government opposition.

“The appeals chamber considers it appropriate to...authorize the investigation,” presiding Judge Piotr Hofmanski said at the court in The Hague. He said prosecutors’ preliminary examination in 2017 had found reasonable grounds to believe war crimes were committed in Afghanistan and that the ICC has jurisdiction.

U.S. Secretary of State Mike Pompeo quickly condemned the decision as “a truly breathtaking action by an unaccountable political institution, masquerading as a legal body”.

“It is all the more reckless for this ruling to come just days after the United States signed a historic peace deal on Afghanistan – the best chance for peace in a generation,” he said.

“The United States...will take all necessary measures to protect our citizens from this renegade, so-called court.”

Afghanistan is a member of the ICC, though Kabul has argued that any war crimes should be prosecuted locally.

The U.S. government has never been a member of the court, which was established in 2002. U.S. President Donald Trump’s administration imposed travel restrictions and other sanctions against ICC employees a year ago.

Prosecutor Fatou Bensouda wants to investigate possible crimes committed between 2003 and 2014, including alleged mass killings of civilians by the Taliban, as well as the alleged torture of prisoners by Afghan authorities and, to a lesser extent, by U.S. forces and the CIA.

FILE PHOTO: U.S. troops assess the damage to an armoured vehicle of NATO-led military coalition after a suicide attack in Kandahar province, Afghanistan August 2, 2017. REUTERS/Ahmad Nadeem

“The many victims of atrocities committed in the context of the conflict in Afghanistan deserve to finally have justice,” Bensouda said after the ruling. “Today they are one step closer.”

UNCERTAIN CHANCES

A pre-trial panel last year had rejected her request to open an investigation. It argued that the odds of success were low, given the passage of time and the lack of cooperation from Kabul and Washington, and said that an investigation would not “serve the interests of justice.”

ICC prosecutors’ initial examination concluded there was a “reasonable basis to believe” U.S. forces had committed “crimes of torture, outrages upon personal dignity and rape and other forms of sexual violence”. The examination cited cases in Afghanistan as well as at secret Central Intelligence Agency facilities in Poland, Romania and Lithuania.

Human rights groups welcomed Thursday’s ruling.

“Too many ICC states have cooperated with the U.S. to set up the global torture program, we now call on these same states to cooperate with the ICC prosecutor’s investigation,” said Katherine Gallagher of the Center for Constitutional Rights.

U.S. forces and other foreign troops entered Afghanistan in 2001 after the Sept. 11 al Qaeda attacks on the United States, and overthrew the Taliban government, which had been protecting al Qaeda leader Osama bin Laden.

In what has become the United States’ longest war, about 13,000 U.S. troops remain in Afghanistan.

The United States and the Taliban signed an agreement on Saturday to withdraw thousands of U.S. troops, but Washington carried out an air strike on Taliban fighters on Wednesday. [uL4N2AX2GL]

The ICC was set up to prosecute war crimes, genocide and crimes against humanity. It has jurisdiction only if a member state is unable or unwilling to prosecute atrocities itself.