It is widely regarded as the world's most potent spyware, capable of reliably cracking the encrypted communications of iPhone and Android smartphones. The software, Pegasus, made by an Israeli company, NSO Group, has been able to track terrorists and drug cartels. It has also been used against human rights activists, journalists and dissidents. Now, an investigation published Friday by The New York Times Magazine has found that Israel, which controls the export of the spyware ... has made Pegasus a key component of its national security strategy, using it to advance its interests around the world. The F.B.I. bought and tested NSO software for years with plans to use it for domestic surveillance until the agency finally decided last year not to deploy the tools. The F.B.I., in a deal never previously reported, bought the spyware in 2019. It also spent two years discussing whether to deploy a newer product, called Phantom, inside the United States. The discussions at the Justice Department and the F.B.I. continued until last summer. But Pegasus equipment is still in a New Jersey building used by the F.B.I. And the company also gave the agency a demonstration of Phantom, which could hack American phone numbers. A brochure ... says that Phantom allows American law enforcement and spy agencies to "turn your target's smartphone into an intelligence gold mine." In 2018 ... the C.I.A. bought Pegasus to help Djibouti, an American ally, fight terrorism, despite longstanding concerns about human rights abuses there.