How they see us: Trump’s wrecking ball theory of foreign policy

"Picture this," The Economist urges in its cover editorial, "Trump’s demolition theory of foreign policy":

"[N]ext week in Singapore President Donald Trump and Kim Jong Un crown their summit with a pledge to rid the Korean peninsula of nuclear weapons. A few days later America and China step back from a trade war, promising to settle their differences. And in the summer, as sanctions bite, the streets of Tehran rise up to cast off the Iranian regime."

• "These gains would be striking from any American president. From a man who exults in breaking foreign-policy taboos, they would be truly remarkable. But are they likely? And when Mr Trump seeks to bring them about with a wrecking ball aimed at allies and global institutions, what is the balance of costs and benefits to America and the world?"

"In the short term some of Mr Trump’s aims may yet succeed. Iran’s politics are unpredictable and the economy is weak. Mr Kim probably wants a deal of some sort, though not full disarmament ... On trade, China would surely prefer accommodation to confrontation."

• "Yet in the long run his approach will not work. ... [R]ules help deter aggressors, shape countries’ behaviour, safeguard American interests and create a mechanism to help solve problems from trade to climate change."