'Instincts for restraint': Senate divided over who gets to declare war

Lawmakers are debating what role Congress should play as the White House weighs its options in Iran. 

Does the legislative body have sole power to declare war, or should that power be ceded to the president?

The back and forth comes as President Donald Trump mulls whether to join Israel in its campaign against Iran or continue pushing for a diplomatic end and return to the negotiating table to hammer out a nuclear deal with the Islamic Republic.

THUNE WARNS IRAN SHOULD RETURN...