Suddenly, Joe Biden says it’s time for us “to get tough with China” — as if that’s not exactly what President Trump has been doing.

And the reverse of where Biden’s stood for his entire career.

“China poses a serious challenge to us, and in some areas are a real threat,” the ex-veep announced Tuesday in Iowa.

But just last month, also in Iowa, he laughed at the idea. “China is going to eat our lunch? Come on, man . . . They’re not bad folks, folks . . . they’re not competition for us.” More: “No other nation can catch us, including China. I got criticized for saying that.”

Last week in New Hampshire, he wailed, “What are we worried about?”

All that fit with the policies he supported for eight years as No. 2 to President Barack Obama, who responded to China’s theft of intellectual property and other clear violations of World Trade Organization rules by . . . asking President Xi Jinping to stop. As if.

Trump has been doing what Team Obama never dared: Calling China to account, and putting all its trade privileges at risk if it doesn’t change. And he’s standing firm: When Beijing reneged on trade concessions last month, he broke off talks and imposed tougher tariffs. He also blacklisted tech giant Huawei as a risk to US national security.

Even as Biden finally is admitting that Trump was right about the problem, he still claims he’s “worried about China . . . if we keep following Trump’s path.” So even while pretending to turn hawkish, he’s still a dove.

This is Biden’s second major flip-flop in a week, after abandoning a career-long position on abortion. He’s been shifting left on a host of other issues, such as climate change, too. Who will Uncle Joe even be by the end of the campaign?