Major geopolitical crises have a way of greeting US presidents soon after taking office. Nazi Germany's withdrawal from the League of Nations in 1933, the Soviet-led construction of the Berlin Wall in 1961, the Gulf of Tonkin incident in 1964 -- all were among the most daunting tests of US foreign policy in the past century, and all came less than a year into the tenures of new US administrations.
This is no accident. Foreign governments often like to test a new White House early on. Indeed, Russia appears to have already commenced its testing of Trump's Washington; a resurgence of heavy fighting in Eastern Ukraine suggests Moscow may be embarking on an offensive that could redraw Ukrainian borders beyond Crimea.
If past is precedent, Beijing will also soon look to stress-test the new White House. How President Trump responds could well determine whether he stays in the driver's seat of his own legacy.