Subversion

Subversion is a systematic attempt to overthrow or undermine a government or political system by people working from within. Subversion generally works against structures of power, authority, exploitation, servitude, and hierarchy. A subversive is something or someone that works against an organization or system.

Subversive activity is the lending of aid, comfort, and support to individuals, groups, or organizations that work for the overthrow of a system. Actions against the best interests of the government, and which are not treason, sedition, sabotage, or espionage may be put in the category of subversive activity. 

There is no agreed definition of subversion. Charles Townshend described subversion as a term "so elastic as to be virtually devoid of meaning, and its use does little more than convey the enlarged sense of the vulnerability of modern systems to all kinds of covert assaults." 

Laws
China
Subversion is a crime in China. The government of the People's Republic of China prosecutes subversives under Articles 102 through 112 of the state criminal law.Silencing Critics by Exploiting National Security and State Secrets Laws . Congressional-Executive Commission on China. These laws describe behavior that can be a threat to national security. China has prosecuted many dissidents using these laws. Articles 105 and 111 are used the most often to silence political dissent. Article 105 makes it a crime to organize, make a secret plan, work against the national order, or tell rumors to make people fight the national order or overthrow the socialist system. Article 111 prohibits stealing, secretly collecting, purchasing, or illegally providing state secrets or intelligence to an organization, institution, or personnel outside the country.Coliver, 1999, p. 245.

United Kingdom
There is no crime defined as "subversion" in British Constitutional law. There is a crime of treason. Legal experts have tried define subversion, but political and legal thinkers could not reach a general agreement.Spjut, R. J. (1979). Defining Subversion. British Journal of Law and Society, 6(2), 254-261Gill, Peter (1994). Policing politics: security intelligence and the liberal democratic state. Routledge. p. 119. 

References

Other websites

"Address before the National Association of Manufacturers" on the Soviet military and political threat  by Allen Welsh Dulles (1959) - lower-middle portion of web page

Category:Society