For all his outsize ambitions, Philippine President Rodrigo Duterte has spoken in remarkably pessimistic terms about his presidency. Duterte has said repeatedly that he does not expect to complete his six-year term -- hinting darkly at assassination plots, brewing coups or attempts at impeachment. He has even suggested that he would be willing to step down as soon as he fulfills certain campaign pledges. In making these statements, Duterte is responding, in part, to the rumors of a prospective military coup that have dogged him since even before he was elected. After all, his controversial outreach to communist rebels and promises to weaken long-standing defense ties with the United States have not endeared him to the military....