Sen. John McCain (R-AZ) (center), Sen. Ben Cardin (D-MD) and Sen. Tim Kaine (D-VA) (left) talk prior to a Senate Foreign Relations Committee hearing on military intervention in Syria, on Capitol Hill in Washington, D.C. on September 3, 2013. UPI/Kevin Dietsch | License Photo

WASHINGTON, Jan. 17 (UPI) -- The evolving nature of warfare means it's time to review the way the White House makes declarations of war, two leading senators said.

Sens. John McCain, R-Ariz., and Tim Kaine, D-Va., introduced legislation that would replace the 1973 War Powers Resolution with a new act that requires congressional input on major conflict involving U.S. military forces.


Both senators said the 1973 measure, largely ignored, is "ineffective."

"As the world becomes more dangerous and complex, and demands continue to increase for American leadership, we need to establish a better system of communication between the president, Congress and the American people, especially on decisions of war and peace," Kaine said in a statement Thursday.

Debates surrounding military engagements since the Vietnam War resurfaced last year when President Barack Obama called for support for some form of military response to the Syrian civil war.

Congress hasn't formally declared war since 1942. McCain said the nature of combat is shifting from one pitting national rivalries against each other into a "murkier" type of warfare.

"It is essential for the Congress and the president to work together to define a new war powers consultative arrangement that both reflects the nature of conflict in the 21st century and is in line with our Constitution," he said in a statement.