On Saturday, at the annual Munich Security Conference, U.S. Vice President Mike Pence began his comments on behalf of “a champion of freedom and a strong national defense who has worked with these members of Congress to strengthen America’s military might and to strengthen the leadership of the free world; I bring greetings from the 45th president of the United State of America, President Donald Trump.”

“Applause” was written on Pence’s script. But in an unscripted moment that reflected the deep, dangerous divide between the U.S. and Europe, the Western political, military and diplomatic delegates reacted with nearly complete silence.

Their reaction spoke volumes. It was no doubt noticed by ally and adversary alike — including Russia and China, ever keen to sharpen the divisions among nations that should be united against the threats that they and other nations, as well as nonstate actors, pose to Western interests.

Any hope that Trump would convert to conventional leadership of the transatlantic alliance seems to have ebbed, or ended. And without buy-in from the boss, empty rhetoric from Pence or other administration officials won’t be believed by adversaries, allies or even Americans concerned that the postwar geopolitical architecture built mostly by the U.S. for the West’s benefit will return.

So others need to speak up.

Former Vice President Joe Biden did in Munich when he said: “The America I see does not wish to turn our back on the world or our closest allies. The America I see cherishes a free press, democracy, the rule of law. It stands up to the aggression of dictators and against strongmen.” Later, to loud applause that contrasted to the silence Trump’s name invoked, Biden added: “This too shall pass; we will be back.”

Biden clarified that he was speaking as a citizen, not as a candidate for president. But many expect him to enter the Democratic donnybrook. If he does, Biden should continue to stress international issues even, and perhaps especially, if his rivals are more domestically driven. Whatever domestic success the country experiences will be directly tied to America’s role in an increasingly interconnected world dependent on defending Western values, governance and security.

Beyond Biden, other former world leaders made their voices heard at Munich when they launched a campaign “to defend democracy and a rules-based order.” The effort, organized by the Atlantic Council and Canada’s Centre for International Governance Innovation, is led by a bipartisan, multinational group that includes former Secretary of State Madeleine Albright, who served in the Clinton administration, and former National Security Advisor Stephen Hadley, who served in the George W. Bush administration, as well as the former prime minister of Sweden and foreign minister of Japan.

Oriented around seven key principles — freedom and justice; democracy and self-determination; peace and security; free markets and equal opportunity; an open and healthy planet; the right of assistance; and collective action — the group hopes to “revitalize a rules-based order and rebuild public support in favor of democracy, open markets, and alliances.”

These enduring objectives shouldn’t be controversial. That the alliances that once upheld them have so rapidly deteriorated should be.

Congress — on a bipartisan basis — should speak up, too. Loudly.

Especially Republicans, whose party once so proudly espoused these values. They should realize the damage Trump is doing, reassert their branch of government’s privilege and responsibility and speak out against the president, even if he’s from the same party.

It’s necessary for all who care about the international institutions and alliances that have brought relative peace and prosperity for decades to defend them. Silence is no longer an option.