The current political situation in Afghanistan makes the prospects for a successful investigation and prosecution "extremely limited," the judges say, citing an ongoing lack of cooperation and the need to devote resources to cases with better chances of success.
Mike Pompeo, Trump's secretary of state, also warned of additional measures including economic sanctions if the court didn't back down on its Afghanistan probe.
The ICC was established as a permanent court of last resort by the United Nations in 2002, charged with prosecuting genocide, war crimes and crimes against humanity when nation states are unable, or refuse, to do so. Its treaty has been ratified by 123 countries so far, including Canada. But powers like Russia, China, Israel, India and Saudi Arabia have refused to sign on, expressing fears that the body would infringe upon their sovereignty.
The Americans have been its fiercest opponents, however.
But the current president and his top advisors are vehemently opposed to the court.
"The ICC is already dead to us," National Security Adviser John Bolton proclaimed in a speech last fall, calling the body "illegitimate," and threatening to ban its judges from the country.
Evidence of U.S. military misdeeds in Afghanistan and Iraq was first put into the public sphere via WikiLeaks in 2010. The ICC's preliminary examination in 2016 concluded that there were reasonable grounds to believe that Taliban, Afghan forces and the Americans have all committed crimes since the conflict began in 2002, singling out incidents of torture by the CIA and U.S. army interrogators.
Today's decision to back away from the investigation is being greeted as an exoneration by the White House.
"This is a major international victory, not only for these patriots, but for the rule of law. We welcome this decision and reiterate our position that the United States holds American citizens to the highest legal and ethical standards,"reads an official statement from the president.
But whatever the ICC's motivation, its choice to move on to other cases throws the tribunal's very future into question.
Right now, there are only two active cases being prosecuted — one involving alleged atrocities against peacekeepers in Darfur, and the other probing reported crimes against humanity by the Lord's Resistance Army in Uganda.
The next big test for the ICC will likely be its ongoing investigation into alleged crimes committed by members of the U.K. military during their occupation of Iraq. The case was initially dismissed in 2006, but reopened after new information surfaced in 2014.
The U.K. has investigated the allegations of its own accord, he said, and has meted out punishments as it has seen fit.
"The Court is not there to second-guess, still less to review, the decisions of competent, functioning national systems of justice," he said. "The Court should step in only where States are genuinely unable or unwilling to do so themselves."