US officials say President Biden has given the green light for Ukraine to use long range missiles supplied by Washington to strike deep inside Russia. Washington had previously refused to allow such strikes with US-made ATACMS missiles because it feared they would escalate the war.

Lyons questioned the timing of the decision, saying, “I’m not sure why we didn’t allow this two or three years ago."

The nuclear doctrine states that final authority to use nuclear weapons rests with the President, and the changes are effective immediately.