U.S., Iran policy depends not just on sanctions but on flexibility

Washington will reintroduce sanctions on Monday targeting Iran's most important industry - oil - and U.S. officials have indicated a measure of flexibility is needed to ensure global markets are well supplied to keep prices from surging.In abandoning the international 2015 Iran nuclear deal, Trump and his top aides have touted the re-imposition of economic penalties on Iran as part of a "maximum pressure" campaign to force a change in a wide range of Iranian behavior.What Trump wants from Tehran