PARIS — Europe is pushing for more stringent vetting of foreign investments, with an eye on Beijing. Australia has been blocking bids by Chinese buyers for strategic assets. And in Canada, a Chinese takeover of a major contractor faces a national security test.

As China looks to spread its wealth and influence, the United States is not the only country seeking to shield its industries under the guise of national security. Governments around the world, and especially in Europe, are increasingly inclined to use such concerns as a litmus test for Chinese investments to protect their competitive edge.

It’s a mixture of political posturing, national pride and outright paranoia. But China presents a difficult policy puzzle. Countries must balance safeguarding their strategic industries and preventing the loss of sensitive technologies, while still courting Chinese investors and improving trade with Beijing.

“There’s a general impression that China is rising on all fronts, and the question is how to deal with that,” said Philippe Le Corre, a China specialist and senior fellow at the Harvard Kennedy School. “Most countries don’t know how to react.”