For decades, Chinese security strategy was aimed at deterring invasion via a huge but relatively low-tech military. When the Chinese economy took off in recent decades, Beijing saw new opportunities to flex its muscles. China’s national security and military strategies shifted toward power projection and contesting U.S. domination of the Asia-Pacific region. One of the most obvious signs of this has been the immense qualitative and technological improvement in the Chinese armed forces. According to a recent Pentagon report, China is pursuing “a long-term, comprehensive military modernization program” and investing in capabilities designed to defeat adversary power projection and counter third-party—including U.S.—intervention during a crisis or conflict.

This growing military prowess allows China to adopt a more assertive policy. Take, for instance, Beijing’s steps to control the South China Sea. The Pentagon report noted that in 2014, China “started reclaiming land and building infrastructure at its outposts in the Spratly Islands” to use as “persistent civil-military bases of operation.” As Bonnie Glaser explained in a report for the Council on Foreign Relations, this is fraught with danger and could spark an armed encounter in a number of ways. While Glaser assumed that direct confrontation is not China’s objective, this is not absolutely certain. Beijing clearly is willing to at least risk a clash with the United States more than it was in the past.

Another form of Chinese aggression is expanded cyberattacks on the U.S. government. These recently reached a new level with the massive penetration of the Office of Personnel Management’s database of security clearance applications. While the Obama administration has stated that it is considering retaliation, it has not yet decided what actions it will take. But the fact that the White House has reached this point indicates the extent of the danger.

What causes concern is the accumulation of these actions by Beijing. History again offers signposts.