The Hillary Clinton caravan has departed China and rolled into India. The main item on her agenda, according to the Financial Times, is to induce her host to further reduce its imports of Iranian oil. India has taken some steps in recent moths to slash its oil purchases from Iran but Clinton said that New Delhi needed to cut back “even more.”India imports more oil from Iran than any other country besides China—some 300,000 barrels per day. India’s acquiescence to American pressure is therefore vital in its own right, but as the FT notes, India’s defiance also makes it harder for the U.S. to convince China to follow suit.The coming weeks are crucial to American diplomatic efforts in the Middle East. The U.S. and its partners are due to meet Iranian negotiators in Baghdad at the end of the month. If the Obama administration is to succeed in persuading Iran to abandon its nuclear ambitions, then it will need to convince Tehran that its major oil buyers will uphold sanctions.