Ellie Cook is a Newsweek security and defense reporter based in London, U.K. Her work focuses largely on the Russia-Ukraine war, the U.S. military, weapons systems and emerging technology.

Marni Rose McFall is a Newsweek reporter based in London, U.K. Her focus is on internet trends, U.S. politics and popular culture. She has covered fashion, culture, art and music extensively.

Here are three weapon systems, and how they could be used. A trio of tanks: the T-72, T-80, T-90 Among the first signs of a buildup of Russian forces along the border with Ukraine was the presence ...