Donald Trump's candidacy has been a source of anxiety for many reasons, but one stands out: the ability of the president to launch nuclear weapons. When it comes to starting a nuclear war, the president has more freedom than he or she does in, say, ordering the use of torture.

It's all too easy to imagine Trump issuing an ultimate, thermonuclear 'You're fired!' to China, Iran, or another nation - and perhaps to the whole human race.

Cabinet members may disagree and even resign in protest, but, ultimately, they must obey the order of the Commander-in-Chief.

Lawrence M. Krauss Quotes