North Korea, a small and poor country facing far stronger adversaries and the perpetual threat of its own collapse, would not seem a likely state to defy four consecutive American presidents.
Yet it is precisely that weakness, analysts say, along with the country’s history and internal dynamics, that drives its leaders to pursue nuclear and missile programs at virtually any cost — and that robs the world of almost any option to limit them.
Those factors, when viewed together, show why Barack Obama warned President Trump that North Korea would be the gravest foreign threat he faced — and why a solution has proved so hard to find.