Poland and Romania are deploying a new weapons system to defend against Russian drones, following a spate of incursions into NATO airspace in recent months that exposed the alliance’s vulnerabilities and put Europe on edge. The American Merops system, which is small enough to fit in the back of a midsize pickup truck, can identify drones and close in on them, using artificial intelligence to navigate when satellite and electronic communications are jammed. As well as being deployed in Poland