President Obama, in advance of his victory in Congress on Thursday on the Iran nuclear deal, focused on centrifuge numbers, uranium stockpiles and the breakout time to build a bomb. But now, as the agreement is carried out, he will face a new battle over how stringently to impose economic sanctions on Iran. To reward Iran for imposing constraints on its nuclear program , the United States agreed to lift many of the crippling sanctions that have blocked the country’s integration into the world economy. But to win over wary Democrats, Mr. Obama promised that he would maintain — and perhaps even increase — sanctions to punish Iran for terrorism, human rights abuses and other “ destabilizing activities in the region .” Many lawmakers have indicated they would like to go further, and they are considering legislative proposals that include renewing the current sanctions against foreign companies […]