President Trump has imagined himself at the center of high-stakes nuclear negotiations since at least the mid-1980s, when he tried, unsuccessfully, to persuade the Reagan administration that it needed a New York real estate deal maker to lead arms-control talks with the Soviet Union.

Reversing a trend toward cutting nuclear stockpiles that dates to the early ’90s, a recent Pentagon report called for ramping up U.S. reliance on nuclear weapons in order to keep pace with an aggressive arms buildup by Russia. Complicating matters, Russian President Vladimir Putin boasted today of having new weapons that could evade U.S. defense systems, taunting that their sophistication would force America to “listen to us now.”

A look at North Korea's latest rounds of missile tests with David Ignatius of the Washington Post, David Sanger of The New York Times, Lionel Barber of the Financial Times, and Nicholas Burns of Harvard's John F. Kennedy School of Government.

"When President-elect Donald J. Trump said on Twitter in early January that a North Korean test of an intercontinental ballistic missile capable of reaching the United States “won't happen!" there were two things he still did not fully appreciate: how close Kim Jong-un, the North’s leader, was to reaching that goal, and how limited any president’s options were to stop him."

Iran’s top nuclear negotiator was heading back to Tehran on Sunday to consult with his nation’s leadership, as negotiators remained divided over how to limit and monitor Tehran’s nuclear program and even on how to interpret the preliminary agreement they reached two months ago.

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.