Saudi Arabia’s Crown Prince Mohammed bin Salman, left. (Yuri Kadobnov/AP)

SAUDI ARABIA has offered a telling response to Canada’s complaint about the arrest of two prominent female activists, Samar Badawi and Nassima al-Sadah. The Saudi Foreign Ministry protested that Canada was engaging in “blatant interference in the Kingdom’s domestic affairs” and an “unacceptable affront to the Kingdom’s laws and judicial process.” The call by Canada to release the women was “reprehensible,” the ministry said. In other words, Saudi Arabia would like the rest of the world to look the other way.

Fortunately, Canada’s foreign minister, Chrystia Freeland, refused. On Aug. 2, she wrote on Twitter that Canada was “very alarmed” about the detention of the two women. Ms. Badawi is the sister of Raif Badawi, a blogger serving a 10-year jail sentence for running a website that was critical of Saudi’s strict religious authorities. Saudi Arabia’s young ruler, Crown Prince Mohammed bin Salman, has been intolerant of dissent and jailed dozens of critics, including intellectuals, journalists and advocates of women’s right to drive . Most have been thrown in jail for long periods without any semblance of due process. When Ms. Freeland called for the Badawis to be freed, the crown prince answered by expelling Canada’s ambassador and severing trade, travel and student exchange links. The intended message: Other countries should mind their own business, or else.

What Ms. Freeland and Canada correctly understand is that human rights and basic liberty are universal values, not the property of kings and dictators to arbitrarily grant and remove on a whim. Saudi Arabia’s long-standing practice of denying basic rights to citizens, especially women — and its particularly cruel treatment of some dissidents, such as the public lashes meted out to Mr. Badawi — are matters of legitimate concern to all democracies and free societies. The crown prince has been impressively active in seeking to modernize the kingdom economically, pushing to diversify away from oil and to satisfy a burgeoning youthful population’s thirst for Western culture and entertainment. Doesn’t he see how this futuristic vision is undermined when he throws critics into dungeons and behaves like a police-state despot?

Unfortunately, the Trump administration has largely withdrawn from the role of championing freedom and human rights abroad. The State Department reacted to the latest news with a depressingly tepid statement, urging both Canada and Saudi Arabia to resolve their differences, adding, “We can’t do it for them.” It is great to see Canada holding aloft the human rights banner, even at the cost of damaged ties to Saudi Arabia. But Canada should not have to do this alone. It is the traditional role of the United States to defend universal values everywhere they are trampled upon and to show bullying autocrats they cannot get away with hiding their dirty work behind closed doors.

Every leading democracy — let’s start with the foreign ministers of the Group of Seven nations — should retweet Ms. Freeland’s post about the imprisoned Badawis. Basic rights are everybody’s business.