A newly drafted United States nuclear strategy that has been sent to President Trump for approval would permit the use of nuclear weapons to respond to a wide range of devastating but non-nuclear attacks on American infrastructure, including what current and former government officials described as the most crippling kind of cyberattacks.

Five former members of President Obama’s inner circle of Iran advisers have written an open letter expressing concern that a pending accord to stem Iran’s nuclear program “may fall short of meeting the administration’s own standard of a ‘good’ agreement” and laying out a series of minimum requirements that Iran must agree to in coming days for them to support a final deal.