With world powers unable so far to win Iran ’s agreement to curb its nuclear program, members of both parties in the new Republican-led U.S. Congress will push in January for more economic sanctions on the Islamic Republic. As the nuclear negotiations continue for an additional seven months, Iran has been promised that it will continue to enjoy limited relief from the existing U.S. sanctions in exchange for continuing to curtail its nuclear efforts under an interim accord signed a year ago yesterday. That sanctions relief has been less valuable to Iran than U.S. officials anticipated, according to figures declassified by the Obama administration in response to requests from Bloomberg News. They indicate that Iran’s direct benefit in cash and non-oil exports in the first six months of this year was about $2 billion less than the administration predicted — $4.6 billion instead of as much as $7 billion, […]