Constantly under attack? Remember that even back when the KMT was in power, Chiang Kai-Shek was (rightfully) suspicious that the CIA was plotting a coup to overthrow him.

Moreover, when the CCP was rising with Mao Zedong, the CIA used something like $100 million USD at the time to try to create a third group in China that could combat the other two (the KMT and CCP) with the explicit goal of undermining Mao's power.

China's existing actions don't even come close to tit-for-tat and America's continued subversive actions show that nothing has changed whatsoever. The US still thinks it can fuck around in the domestic affairs of other countries and leave unscathed without retribution.