A Russian lawmaker calls President Biden's decision to let Ukraine fire U.S. missiles deep into Russia a "very big step toward the beginning" of a third world war.

After U.S. President Joe Biden gave the go-ahead for Ukraine to wield long-range American missiles deep inside Russia, as a Newsweek map illustrates, questions remain over just how much of a difference this will make as Moscow gains in the east and a new U.S. presidential term approaches.