Ukraine has been hit by a surge in Russian ballistic missile attacks, about a third of which used North Korean weapons that can only fly because they run on Western circuitry, obtained despite sanctions,

Two days ago, Russian President Vladimir Putin announced a change in the country's policy for employing nuclear weapons in conflict. Then, on Thursday, Russia attacked the Ukrainian city of Dnipro with a new type of ballistic missile capable of one day delivering multiple nuclear warheads to distant targets with little warning.

The United States believes that Russia fired a never-before-fielded intermediate-range ballistic missile on Thursday in its attack on Ukraine, an escalation that analysts say could have implications for European missile defense.