David A. Andelman

Opinion columnist

Donald Trump is in Asia for the longest tour of the region by any American president in a quarter century, but with a challenge few others have faced — navigating a series of red lines that have been drawn across the region. And most of these deeply troubling diplomatic and military obstacles are of his own making.

The success of most red lines, and the political and diplomatic standing of those who draw them, is based on a willingness to follow through on the threats they make. Until now, Trump has been most successful in his diplomatic red lines. He threatened to withdraw from the Paris climate pact and unwind pollution control regulations crafted by his predecessors — and he did. In Syria, he pledged to carry through on the disastrous red line established by Barack Obama, sending a flotilla of cruise missiles against the military forces of Bashar Assad when the Syrian dictator, once again, used chemical weapons on his own people.

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But in Asia, the red lines are far more intricate, and the consequences of crossing them potentially far more lethal than anything Trump has encountered to date. “Trump may prove to be a ‘wild card’ in the carefully orchestrated and balanced geopolitics of the region, and vis-a-vis North Korea,” says Annelise Riles, director of Cornell Law School’s Clarke Program in East Asian Law and Culture. She says people in both Japan and South Korea are “far less anxious and fearful about the possibility of a nuclear attack than most Americans are, ironically.” Still, they’ll have to live with the consequences, which could prove quite frightening indeed.

North Korea has already violated the airspace at Trump’s first stop, Japan, by sending an intercontinental missile across its territory on a test flight. While it carried no nuclear weapon, it was of a type that could certainly do so in the future. So how did Trump react to this threat to an ally he has said he values most deeply? With a direct challenge. “We dominate the sky, we dominate the sea, we dominate the land and space,” Trump proclaimed to American troops at Yokota Airbase when he landed in Japan late Saturday. “We have the best people. Each of you embodies the warrior creed. Your devotion, prowess and expertise make you the most fearsome fighting force in the history of our world.”

For a nation like Japan, which has feared Trump’s expectation that he wants every ally to do more for its own defense, those words about U.S. strength could be read as reassuring. But they could be frightening for South Korea, Trump’s next stop and the nation most directly in the cross-hairs every day of North Korean military might. Of all the red lines, as described by Trump’s national security adviser, H.R. McMaster, this is the most inviolable. “The United States remains committed to the complete, verifiable, and permanent denuclearization of the Korean Peninsula.” No middle ground, no compromise. For Pyongyang, that’s already being portrayed as an existential threat. North Korea leader Kim Jong-un is known to have taken very seriously to heart what happened to Libyan dictator Moammar Gaddafi when he renounced his nuclear ambitions. He wound up in a drainage ditch, executed by rebels.

Chinese leader Xi Jinping, whom Trump describes as "a very good man," would no doubt welcome a denuclearized Korea (North and South). But he is unlikely to welcome two other Trump red lines — an end to Chinese efforts to dominate the South China Sea, as well as fairer, more open trade that gives U.S. businesses more access to Chinese markets.

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Indeed, Trump’s very adoption of the phrase “Indo-Pacific” in lieu of the traditional “Asia-Pacific” is a suggestion that if China does not respect Trump’s red lines, there is another Asian nation — India — that’s more than willing to assume a leadership role in China’s backyard.

In his final two stops in Vietnam and the Philippines, as well as at conferences of the entire range of Asian nations, including Russia, Trump will have to persuade all of them that he recognizes and values their interests. Every nation he visits faces existential threats. A record high stock market and low unemployment, which Trump highlighted the moment he left Air Force One at Yokota, may not convince them that this president can make good on his threats, deliver on his promises and enforce his priorities. The challenge was underscored when the Pentagon, while Trump was still in the air, released a report to Congress that concludes the only way to assure the end of North Korea’s nuclear arsenals would be a full-scale ground invasion.

Perhaps Trump’s only concession to so many large egos and sensitive issues involving China, North Korea and South Korea? Refraining from a visit to the DMZ, where North Korean and American troops stare each other down every moment of every day. But it will take far more than a gesture to emerge a winner from these 12 days in Asia.

David A. Andelman, a member of USA TODAY's board of contributors, is the author of A Shattered Peace: Versailles 1919 and the Price We Pay Today. He formerly was a foreign correspondent for The New York Times in Asia and Europe, and Paris correspondent for CBS News. Follow him on Twitter @DavidAndelman