WASHINGTON (Reuters) -- The United States is ready to consider all options for how it would deal with a world in which Iran were not willing to return to the constraints of the 2015 nuclear deal, U.S. Special Envoy for Iran Rob Malley said on Wednesday. “We will be prepared to adjust to a different reality in which we have to deal with all options to address Iran’s nuclear program if it’s not prepared to come back into the constraints,” of Tehran’s 2015 nuclear deal with six major powers,” he said in a virtual appearance at a Washington think tank.