Tit-for-tat moves this week included the use of American-made ballistic missiles to strike inside Russia, and new nuclear threats from Moscow. Neither appear to have influenced the war on the ground.

President Vladimir Putin said Friday that Russia will continue to test and start mass-producing the hypersonic ballistic missile that it fired at Ukraine Thursday.

Russia fired a hypersonic intermediate-range ballistic missile at the Ukrainian city of Dnipro on Thursday in response to the U.S. and UK's allowing Kyiv to strike Russian territory with advanced Western weapons,