Friend and foe alike are letting their telephones just ring when President Biden calls, a dance of disrespect that endangers security for our citizens here at home.

Far from delivering on his “America’s back” slogan, the president has shown weakness on the world stage, beginning by bungling the end of the war in Afghanistan. In the most recent retreat, he chided Speaker Pelosi for planning last week’s trip to Free China, because Communist China objected. 

Despite Mr. Biden’s show of sympathy, the Xi regime threw a temper tantrum, popping off missiles and holding war games in the waters around the Republic of China. Hoping to tone down tensions, the White House tried to contact Beijing, but as Politico reported, the phone just rang: “Chinese military officials have not returned multiple calls from their American counterparts this week as a crisis erupted in the Pacific over House Speaker Nancy Pelosi’s visit to Taiwan, according to three people with knowledge of the attempts.”

This left America’s Navy, deployed in the South China Sea, in the dark — raising the danger of an incident — and left Communist China’s threat to shoot down the speaker’s plane stand unchallenged.

This cold shoulder follows last year’s scandal when the chairman of the Joint Chiefs of Staff, Army General Mark Milley, was shown to have held secret phone calls with the top man in the People’s Liberation Army, General Li Zuocheng.

“If we’re going to attack,” General Milley said, according to the book “Peril,” by Bob Woodward and Robert Costa, “I’m going to call you ahead of time. It’s not going to be a surprise.”

Despite this promise to subvert the chain of command, made due to paranoia that President Trump would start a war, Mr. Zuocheng doesn’t see this inside track as a two-way street.

When Russia invaded Ukraine in March, the White House also attempted dialogue to reduce the chance of mistake, miscalculation, or malice sparking World War III. “Repeated attempts by the United States’ top defense and military leaders to speak with their Russian counterparts,” the Washington Post reported, “have been rejected by Moscow for the last month, leaving the world’s two largest nuclear powers in the dark….”

 This silence is unprecedented in the nuclear era. Even during the Cuban Missile Crisis, the Kremlin and White House kept lines of communication open between our two leaders.

In Pyongyang, the story was the same. Vox reported two months after Mr. Biden’s inauguration, “The Biden administration may have newly rejoined the global village. But the usually rowdy North Korean neighbors so far have greeted the Americans’ move-in with nothing but silence.”

Reuters reported, “The disclosure of the so-far unsuccessful U.S. outreach raises questions about how Biden will address mounting tensions with Pyongyang over its nuclear weapons and ballistic missile programs.”

One might expect communist dictatorships to ignore Mr. Biden, but he has fared little better when speed-dialing allies.

As gasoline prices began their climb to record highs this past spring, the president called the United Arab Emirates and Saudi Arabia for relief. When both nations let the calls go to voicemail, it was too much even for Trevor Noah, left-wing host of “The Daily Show.”

“Apparently,” he said, “Saudi Arabia won’t even pick up the phone for the president of the United States. You can say what you want, but this would have never happened to Donald Trump.”

We’ve all had a falling out or two in our lives, and when they happen, sometimes we refuse all communication with the other party, or even “ghost” them, in the parlance of our times. We only pick up when we have something to lose for not working things out with that spouse, boss, friend, or business partner.

Other nations don’t think they’ll pay a price for ignoring the American president, so when caller ID shows his number, they treat him as the equivalent of a spammer.

Mr. Biden rode into office promising a sure-footedness at international relations, but like the tango, diplomacy requires two — and when another nation refuses to dance, it’s sending a message that speaks louder than words.