The Constitution has been shredded to the point where the president has thumbs-up or thumbs-down power to decide who shall live and who shall die. From Andrew P. Napolitano at antiwar.com:
The Biden administration is killing people, openly in Ukraine and Gaza and secretly around the world. It has continued to use the killing machinery crafted by President George W. Bush, expanded by President Barack Obama and employed by President Donald Trump. These presidents have used drones and other unmanned projectiles to target persons in foreign countries with which the United States is not at war.
They have done this notwithstanding the prohibition against taking life, liberty or property from any person – not just any American, but any person – in the Constitution each has sworn to uphold, and they have done so pursuant to secret rules that they themselves have established for these killings.
Last year, 11 senators and 39 members of the House of Representatives sent a harshly worded letter to President Joe Biden asking him to stop the secret, but not the public, killings. As of this writing, he has not publicly replied.
Here is the backstory.
The purpose of the Bill of Rights – the first 10 amendments to the Constitution – is to protect personal liberty by restraining the government.
The Fifth Amendment prohibits killing persons, restraining liberty and taking property without due process; that means a jury trial at which the government must prove criminal behavior or fault, depending upon its goal.
If the country is at war – lawfully and constitutionally declared by Congress – obviously the president can use the U.S. military to kill the military of the opposing country. And if an attack on the U.S. is imminent, the president can strike the first blow against the military of the entity whose attack is just about to occur.
There are no other constitutional circumstances under which a president may kill.