Who would have imagined that a tweet could have sparked such a crisis in Saudi-Canada relations? In this still-developing saga, there is a lesson, questions and a challenge.

The lesson is obvious: Diplomacy by tweet is a bad idea.

The too-clever-by-half tweet on the Friday before the August long weekend was likely written to assuage constituent pressures – the Montreal family of the imprisoned Badawis. But was it given sufficient scrutiny by our professional diplomatic corps?

The tweet would have been fine had it been sent by Amnesty International or Human Rights Watch. Diplomacy needs nuance and circumspection to effect actual change. While a useful social-media tool for priming an event or announcement, 280 characters are insufficient for launching a human-rights initiative to transform Saudi conduct.

The questions: Did Mohammed bin Salman, the Saudi Crown Prince calling the shots in the desert kingdom, check with U.S. President Donald Trump before proceeding with his attack on Canada? Given their close personal relationship – Mr. Trump’s first foreign visit was to Riyadh – was there a conversation before the Saudis launched the diplomatic equivalent of DEFCON 3 on the United States’ closest ally? If so, what was said?

Prime Minister Justin Trudeau needs to call Mr. Trump to discuss the Saudi situation. If it turns out that Mr. Trump gave the Crown Prince a wink and a nod to proceed, then Mr. Trudeau needs to make it clear that this is not acceptable.

The challenge for Canada is what to do next.

The Saudis are ratcheting up their campaign. Their social media have called Canada an oppressor of women and the homeless. The tweeted picture of an Air Canada jet headed for the CN Tower – shades of the Twin Towers – was reprehensible. The Saudis are also calling in their chits. The Arab League, Organization of Islamic Co-operation and the Gulf Co-operation Council have all dutifully lined up behind Saudi Arabia. The Saudi Arab News says Mr. Trudeau should send a delegation on “the first plane” to make amends or there is a “real risk of upsetting the entire Muslim and Arab worlds.”

The Washington Post editorialized (with an Arabic version) that the extreme nature of the Saudi punitive actions requires solidarity from like-minded countries who see human rights as a fundamental value.

The response to date from our Group of Seven partners is disappointing. The U.S. State Department suggested the two countries – “both close allies of the USA” – work it out, as though Canada and Saudi Arabia were on equal footing. Susan Rice, who served as president Barack Obama’s UN Ambassador and then National Security Adviser, got it right: ”the administration left Canada swinging in the wind.”

Foreign Affairs Minister Chrystia Freeland now has to manage the fallout and continue her efforts to persuade like-minded countries to take a principled stand.

Are there sanctions we and our allies should be taking against the Saudis for their human-rights abuses, including treatment of women, oppression of religious freedoms and their intervention in Yemen? And why not invite its Foreign Minister to Canada? Perhaps he could join Ms. Freeland for a walk through our splendid Canadian Museum for Human Rights in Winnipeg.

Ms. Freeland has given some good, punchy speeches defending the rules-based order recently, in Washington and in Singapore. Words matter. On her next trip to Europe, she should speak about human rights and remind our allies that they are fundamental to civil society. Mr. Trudeau should make human rights a principal theme of his UN General Assembly speech in September.

It is doubtful the Trudeau government intended to launch a new initiative targeting Saudi human rights. It already has a charged foreign-policy agenda – tense NAFTA negotiations, NATO commitments, climate talks, G7 chair obligations, peace operations in Mali and now refugee claimants from the United States. But Saudi bully-boy tactics shouldn’t give the kingdom a free pass on human rights.

As we have learned through our initiatives to help the Rohingya in Myanmar and to constrain the Maduro regime in Venezuela, advancing human rights in countries that don’t care is a difficult proposition. But if a feminist foreign policy and advocacy for human rights is to mean anything, we have to stand up, even if we stand alone.