African American culture decades ago included an informal, spontaneous game called the Dozens, in which participants would use insults and boasts to prove their superior wit. President Trump would be good at the boasting part. But his tendency to brag when straight talk is needed makes him a dangerous commander-in-chief. Like his predecessor, he will learn the folly of drawing lines in the sand that fade.

Americans aren't so insecure that they need their president to get into a boasting match with North Korean dictator Kim Jong Un, a murderous despot whose depravity suggests derangement. Rather than stoop to Kim's level, Trump would better serve his country by calmly exhibiting fortitude.

North Korea's development of a missile that could reach the continental United States makes his threats of a nuclear attack more credible than those of his ancestral antecedents, who consistently used that strategy, rather than resorting to begging, to get help when their destitute nation faced food shortages.

The United Nations in January sent $8 million in aid to North Korea, where of 18 million people, 70 percent of the population is considered food insecure, nearly 30 percent of all children under age 5 are suffering from chronic malnutrition, and 4 percent of all children under 5 are acutely malnourished or "wasting." That means they are on death's door.

Who other than a madman would spend billions of dollars to build a nuclear weapon while his emaciated people die from lack of food? Kim's madness may mean he is incapable of being reasoned with. Being so close to the nuclear weapons goal his father never achieved may mean he will never retreat. But is this really the time for Trump's brinksmanship?

The president lowered the volume on his rhetoric after world leaders reacted negatively to his threat Tuesday that further provocations by North Korea "will be met with fire and fury like the world has never seen." But after Pyongyang responded with a threat to strike Guam, Trump was again rattling sabers. "Things will happen to them like they never thought possible," he said Thursday.

That's not necessarily an idle boast. The U.S. is certainly capable of destroying North Korea. But that goes without saying. As another president, Teddy Roosevelt, observed 100 years ago, when you carry a big stick you don't have to boast about it. But Trump just can't help himself. It's clear that boasting is second nature to him. He's not himself if he isn't bragging.

After his first 100 days, he boasted that he had signed more bills than any president since Harry Truman. But most of what Trump signed was routine legislation, like the official naming of a federal courthouse in Tennessee. In their first 100 days, Truman ended World War II, John Kennedy established the Peace Corps, Bill Clinton signed the Family and Medical Leave Act, and Barack Obama signed the $800 billion stimulus that helped end the recession.

Psychology Today contributor Andrea F. Polard says one of the best ways to quiet a braggart is to walk away. That won't work with Trump. Pretending what the president says doesn't matter denies reality. There is a learning curve for every new president. All Americans must hope Trump one day will listen when advised to take care when he speaks.