One thousand days ago, Russia launched its full-scale invasion of Ukraine. Ukraine marked that grim milestone with a first, using a long-range American missile system to hit a target inside Russia. Also Tuesday, Russia updated its nuclear doctrine that says it could use nuclear weapons if attacked by a conventionally armed country supported by a nuclear power. Nick Schifrin reports. PBS News is supported by - https://www.pbs.org/newshour/about/funders