LAST WEEK, some of the world’s autocrats came to town for the Nuclear Security Summit , men who have thrown their critics in prison and destroyed the fabric of civil society. They got polite treatment from the Obama administration. They deserved worse.

Take President Ilham Aliyev of Azerbaijan, who has regularly imprisoned his critics. He released a batch of prisoners before the summit, perhaps thinking that would take the edge off, although investigative journalist Khadija Ismayilova remains behind bars for no good reason and rights activists Leyla and Arif Yunus are barred from leaving the country. When Secretary of State John F. Kerry appeared in the Treaty Room with Mr. Aliyev, the secretary offered praise for his guest as a leader in a complex region who has been “very studious and thoughtful.” Mr. Kerry and Mr. Aliyev spoke about energy, the conflict with Armenia over Nagorno-Karabakh and Azerbaijan’s role in Afghanistan. About democracy and human rights, they said nothing.

Vice President Biden also met with the Azeri president, and, according to a statement, “welcomed the recent releases from prison of human rights and civil society activists” and “encouraged continued progress, underscoring the importance of civil society and rule of law.” This is the polite, aspirational approach. In fact, Mr. Aliyev does not respect civil society or rule of law. Would it have been so hard to speak out for Ms. Ismayilova in public?

President Recep Tayyip Erdogan of Turkey also has been attempting to silence his critics, including by means of a steadily closing vise on press freedom with the prosecution of journalists Can Dundar and Erdem Gul. Mr. Biden has spoken out against the press crackdown previously, but it was not mentioned in the statement issued by the White House after his meeting with Mr. Erdogan at the St. Regis Hotel. Nor did the crackdown come up in the White House’s description of President Obama’s meeting with Mr. Erdogan on Thursday evening. After the summit ended Friday, Mr. Obama said he warned Mr. Erdogan against the “repression of information and shutting down democratic debate.”

President Xi Jinping of China discussed climate change, cyber-conflict and nuclear security with Mr. Obama, according to the White House statement that followed their meeting. Mr. Obama “reiterated America’s unwavering support for upholding human rights and fundamental freedoms in China,” the statement said. Mr. Xi does not share those values; he leads a party-state that does not respect individual rights or freedom. Mr. Obama might have named a few names, such as that of his fellow Nobel Peace laureate, Liu Xiaobo, who is rotting in prison for having sought freedom of expression and respect for human rights. Such direct talk might have offended Mr. Xi, but it also would have bolstered the spirits of brave dissidents everywhere who are repeatedly told by their jailers that the world has forgotten them.

Freedom is under siege from China to Russia to the Middle East. Now more than ever, the United States should speak up for individuals who continue to fight for liberty. Private conversations have value, but public messaging does, too. Even at the risk of being rude at a summit, it is critical to remind the tyrants — and indeed the world — that the human spirit can’t be crushed.