PARIS – For America's allies and rivals alike, the chaos unfolding during Donald Trump's final days as president is the logical result of four years of global instability brought on by the man who promised to change the way the world viewed the United States.From the outside, the United States has never looked so vulnerable — or unpredictable.Alliances that had held for generations frayed to a breaking point under Trump — from his decision to back out of the Paris climate accord and the Iran nuclear deal, to quitting the World Health Organization amid a pandemic.And then, by seeking to overturn his loss to Joe Biden, Trump upended the bedrock principle of democratic elections that the United States has tried — and sometimes even succeeded —.