President Barack Obama. Photo: Wikimedia Commons.

More than half of the U.S. Senate has signed a letter urging President Barack Obama to re-emphasize his “readiness to take military action against Iran if it continues its efforts to acquire a nuclear weapon.”

While Obama has stated that “all options are on the table” for the Iranian threat, his administration has repeatedly expressed that there remains “time and space” for tactics such as diplomacy and sanctions to work before resorting to a military option. Additionally, despite the requests of Israeli Prime Minister Benjamin Netanyahu, Obama has refused to set the “red line” which, if crossed by Iran, would prompt U.S. military action.

Sens. Robert Menendez (D-NJ), Joe Lieberman (I-CT) and Kelly Ayotte (R-NH) initiated a letter signed by 57 senators stating that despite bipartisan work on “the most stringent sanctions ever against Iran” during the past four years, the Islamic Republic has “quintupled its stockpile of low-enriched uranium since 2009,” has more than doubled its number of centrifuges at the hardened Fordow enrichment facility since this summer, and continues “to reject the demands of the International Atomic Energy Agency, including refusing to allow inspectors to visit sites where nuclear weaponization work is suspected to have occurred.”

The U.S., therefore, should “make use of all elements of our national power to pressure Iran,” the letter said, urging Obama to “work with our European and Middle Eastern allies to demonstrate to the Iranians that a credible and capable multilateral coalition exists that would support a military strike if, in the end, this is unfortunately necessary.”

Regarding a U.S. red line for the Iranian threat, Obama told rabbis from across the denominational spectrum in a conference call before Rosh Hashanah this year that “no leader wants to tie his hands” by setting such conditions. On the CBS “60 Minutes” program, he went on to describe Netanyahu’s calls for a red line as “noise.”