PRAGUE — In an attempt to push back against attempts to limit its reach in Europe, the Chinese technology giant Huawei threatened legal action against the Czech Republic if its cybersecurity agency did not rescind its warning about the risk the company poses to the nation’s critical infrastructure.

As nations across Europe take the first steps to reconfigure the systems that control the internet, Huawei’s threat was the latest salvo in the escalating war over who will control the hardware that will underpin the new 5G, or fifth-generation, networks.

For more than a year, the United States has been engaged in a global campaign aimed at limiting the reach of Chinese telecommunication firms, contending that they pose a threat to security.

While American officials have not offered specific details to support their concerns, they have pointed to China’s National Intelligence Law, passed in 2017. They say the law requires Chinese companies to support, provide assistance to and cooperate in Beijing’s national intelligence work, wherever they operate.