Calvin Coolidge, during one stretch of his presidency, was getting 15 hours of shut-eye each day, while William Howard Taft was known for nodding off during public events.
President Trump says an alliance with Saudi Arabia is necessary, despite evidence the country's crown prince ordered the killing of journalist Jamal Khashoggi.
NATO leaders meet in Belgium today; many are worried about US President Trump's habit of breaking diplomatic norms. History is filled with other leaders acting bullishly, often with poor results.
America finds itself in uncharted territory under Donald Trump – not least when it comes to climate change and Israel policy.
President Obama has set aside more water and land than any president in history. But he didn't invent unilateral presidential powers.