U.S. weighs grim options if nuclear talks with Iran collapse

According to European diplomats, former U.S. officials and experts, the possible options include:

Persuading China to shut off oil imports from Iran.
Ramping up sanctions, including targeting oil sales to China.
Pursuing a less ambitious interim nuclear deal.
Launching covert operations to sabotage Iran’s nuclear program.
Ordering military strikes against Iran’s nuclear facilities or supporting Israeli military action.