WASHINGTON

PRESIDENT OBAMA has refused to tell Congress or the American people why he believes the Constitution gives, or fails to deny, him the authority to secretly target and kill American citizens who he suspects are involved in terrorist activities overseas. So far he has killed three that we know of.

Presidents had never before, to our knowledge, targeted specific Americans for military strikes. There are no court decisions that tell us if he is acting lawfully. Mr. Obama tells us not to worry, though, because his lawyers say it is fine, because experts guide the decisions and because his advisers have set up a careful process to help him decide whom he should kill.

He must think we should be relieved.

The three Americans known to have been killed, in two drone strikes in Yemen in the fall of 2011, are Anwar al-Awlaki, a radical Muslim cleric who was born in New Mexico; Samir Khan, a naturalized American citizen who had lived in New York and North Carolina, and was killed alongside Mr. Awlaki; and, in a strike two weeks later, Mr. Awlaki’s 16-year-old son, Abdulrahman al-Awlaki, who was born in Colorado.

Most of us think these people were probably terrorists anyway. So the president’s reassurances have been enough to keep criticism at an acceptable level for the White House. Democrats in Congress and in the press have only gingerly questioned the claims by a Democratic president that he is right about the law and careful when he orders drone attacks on our citizens. And Republicans, who favor aggressive national security powers for the executive branch, look forward to the day when one of their own can wield them again.