Sen. Rand Paul (R-Ky.) tweeted on Friday that President Trump should have asked for congressional approval before authorizing a drone strike that killed an Iranian military commander and one of the regime's most powerful figures, Qasem Soleimani.

"If we are to go to war w/ Iran the Constitution dictates that we declare war. A war without a Congressional declaration is a recipe for feckless intermittent eruptions of violence w/ no clear mission for our soldiers. Our young men and women in the armed services deserve better."

Why it matters: Paul's disapproval stands in contrast to his usual support of Trump and his policies, including when the president announced in October he would begin removing U.S. troops from Syria.

Republican hawks like Sens. Marco Rubio and Tom Cotton have spoken out in favor of Trump's actions.

Democratic leaders and 2020 Democratic candidates have unanimously stated that the airstrike was brash and concerning for U.S. foreign relations.

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