Five former senior Iran advisers to President Obama have written an open letter expressing concern that the nuclear accord pending “may fall short of meeting the administration’s own standard of a ‘good’ agreement” and laying out a series of minimum requirements of Iran. 

Among them is former White House adviser Dennis B. Ross, former CIA Director David Petraeus, Robert Einhorn, a former State Department proliferation expert, Gary Samore, Obama’s former chief adviser on nuclear policy, and Gen. James Cartwright, a former vice chairman of the Joint Chiefs of Staff. Among Republicans, the most notable signatory is Stephen Hadley, Mr. Bush’s national security adviser in his second term.

The letter was published Thursday as Secretary of State John Kerry headed for Vienna to attend the last week of negotiations for a final nuclear accord with Iran.