China poses a significant and evolving cybersecurity threat to U.S. critical infrastructure, according to the Cybersecurity and Infrastructure Security Agency (CISA). This threat has transformed considerably over the past two decades, shifting from primarily espionage-focused activities to a potential for disruptive and destructive attacks.

Early warnings about the vulnerability of internet infrastructure were sounded as far back as 1998, during a congressional hearing featuring cybersecurity experts like Cris Thomas (Space Rogue) and Peiter Zatko (Mudge) of L0pht Heavy Industries. They highlighted the difficulty in creating foolproof defense systems and the challenges in tracing cyberattacks.

By the early 2000s, Chinese cyber espionage targeting U.S. government entities became evident, with operations like Titan Rain impacting agencies such as the Departments of State, Homeland Security, and Energy. CISA Director Jen Easterly, reflecting on her experience investigating terrorist use of technology in Iraq, noted the evolving landscape of cyber threats.

Initially, the U.S. focused on defensive cyber strategies, primarily concerned with nation-state adversaries like China, which was then viewed as an espionage threat. However, China's cyber activities intensified, expanding beyond government targets to include the private sector, notably telecommunications companies.

Instances like Operation Aurora in 2010 demonstrated China's increasing reach, impacting companies like Yahoo, Morgan Stanley, and Google. This campaign led Google to withdraw its operations from China. Over time, evidence revealed China's growing interest in critical infrastructure, both within the U.S. and internationally.

Director Easterly expressed concern over this shift towards potential disruptive and destructive attacks, particularly in the context of a potential crisis in the Taiwan Strait. Taiwan's critical role in semiconductor production makes it a prime target, and China has been observed targeting various points in the semiconductor supply chain.

The potential consequences of such attacks are significant, ranging from infrastructure disruptions to societal panic. Easterly emphasized the importance of collaboration between government agencies, the private sector, and international partners to counter this escalating threat.