President Trump told the American people that confronting China would be quick and painless and would result in clear gains for the American economy, a philosophy summarized most famously in his Twitter boast: “Trade wars are good, and easy to win.”

Today, two years after the Trump administration imposed its first punitive measures on China, the United States is mired instead in an escalating trade conflict with no clear strategy, no discernible goals and no end in sight.

Mr. Trump announced last week that he would impose a 10 percent tariff on $300 billion of Chinese imports to the United States. He already had imposed a 25 percent tariff on about $250 billion of Chinese imports. China’s immediate response was to allow the exchange value of the yuan to fall against the dollar, which has the effect of offsetting the tariffs by reducing the price of Chinese goods in dollars. The Trump administration, in turn, issued a finding that China was engaged in currency manipulation.

The sparring briefly unsettled financial markets, but perhaps more worrisome than the fast-twitch response of stock market algorithms is the lack of a broader panic — the sense that this trade conflict is becoming the new normal.