Russia, China and many European states are seen as having the know-how to make basic microwave weapons that can debilitate, sow noise or even kill. Advanced powers, experts say, might accomplish more nuanced aims such as beaming spoken words into people’s heads. Only intelligence agencies know which nations actually possess and use such unfamiliar arms.
The basic weapon might look like a satellite dish. In theory, such a device might be hand-held or mounted in a van, car, boat or helicopter. Microwave arms are seen as typically working over relatively short distances — across the length of a few rooms or blocks. High-powered ones might be able to fire beams across several football fields, or even for several miles.
The episode in Cuba
The Soviet collapse in 1991 cut Russia’s main ties to Cuba, a longtime ally just 90 miles from the United States. The shaky economy forced Moscow to stop providing Havana with large amounts of oil and other aid.
Vladimir Putin, as Russia’s president and prime minister, sought to recover the economic, political and strategic clout that the Soviets had lost. In December 2000, months after the start of his first presidential term, Mr. Putin flew to the island nation. It was the first visit by a Soviet or Russian leader since the Cold War.
He also sought to resurrect Soviet work on psychoactive arms. In 2012, he declared that Russia would pursue “new instruments for achieving political and strategic goals,” including psychophysical weapons.
In July 2014, Mr. Putin again visited Cuba. This time he brought a gift — the cancellation of some $30 billion in Cuban debt. The two nations signed a dozen accords.
A Russian spy ship, Viktor Leonov, docked in Havana on the eve of the beginning of reconciliation talks between Cuba and the United States in early 2015, and did so again in subsequent years. Moscow and Havana grew so close that in late 2016, the two nations signed a sweeping pact on defense and technology cooperation.