Towards the end of Tuesday night’s Democratic presidential primary debate, Sen. Elizabeth Warren (D-MA) explained that she wants to implement a “No First Use” policy which would explicitly rule out the United States ever striking first with nuclear weapons.

After noting that President Obama had previously considered this protocol before eventually deciding against it, CNN moderator Jake Tapper asked Warren why the U.S. should “tie its own hand with that policy.”

“Because it makes the world safer. the United States is not going to use nuclear weapons we need to say so to the entire world,” Warren replied. “It reduces the likelihood someone miscalculates or misunderstands. Our first responsibility is to keep ourselves safe.” She further noted that under President Trump’s watch, there has been an expansion of the different ways “we have nuclear weapons” and the “different ways they can be used.”

Warren would go on to say that the U.S. cannot create trust around the world by threatening to be the first to use a nuclear weapon, adding that America has to “have an announced policy” after Trump pulled out of the Iran nuclear deal.