Political warfare
Tools: 

Peaceful: Political warfare utilizes all instruments short of war available to a nation to achieve its national objectives. The best tool of political warfare is "effective policy forcefully explained", or more directly, "overt policy forcefully backed". But political warfare is used, as one leading thinker on the topic has explained, "when public relations statements and gentle, public diplomacy-style persuasion—the policies of 'soft power'—fail to win the needed sentiments and actions" around the world.
The major way political warfare is waged is through propaganda. The essence of these operations can be either overt or covert. White propaganda is maximally overt: there is attribution to a promoter; the attributed promoter and the actual promoter are one and the same; and no attempt is made to hide the fact that a viewpoint or "line" is being promoted. Most television advertisements are white propaganda turned to commercial ends.  Grey propaganda ranges in overtness from maximal to a slightly lesser degree: as in white propaganda, there is honest attribution to a source; but it differs from white propaganda by being less forthright either about the link between the source and the line being promoted or about its status as propaganda in the first place. Grey propaganda has alternatively been defined as the "semiofficial amplification of a government's voice"; guerilla advertising uses the tools of grey propaganda to sell products and services, while in public service, examples include Radio Free Europe and Radio Liberty (established during Cold War I). Black propaganda is covert: this may be limited to the anonymous dissemination of internally consistent talking points (differing from white propaganda only in its lack of credited authorship), but it may also be the impersonation of a widely trusted organization (through the use of its branding, corporate style guide, distinctive turns of phrase, etc.) under a false flag, or a strategy as complex as the use of a botnet to inundate a social network with self-contradictory disinformation as if through a firehose of falsehood, amplifying the botnet's posts with so-called Likes and Retweets, and frustrating genuine users' bona fide searches for pertinent information by diminishing the signal-to-noise ratio. What unifies these disparate strategies implementing black propaganda is that, in all cases, it "appears to come from a disinterested source when in fact it does not".
There are channels which can be used to transmit propaganda. Sophisticated use of technology allows an organization to disseminate information to a vast number of people. The most basic channel is the spoken word. This can include live speeches or radio and television broadcasts. Overt or covert radio broadcasting can be an especially useful tool. The printed word is also very powerful, including pamphlets, leaflets, books, magazines, political cartoons, and planted newspaper articles (clandestine or otherwise). Subversion, agents of influence, spies, journalists, and "useful idiots" can all be used as powerful tools in political warfare.

Aggressive: Political warfare also includes aggressive activities by one actor to offensively gain relative advantage or control over another. Between nation states, it can end in the seizure of power or in the open assimilation of the victimized state into the political system or power complex of the aggressor. This aggressor-victim relationship has also been seen between rivals within a state and may involve tactics like assassination, paramilitary activity, sabotage, coup d'état, insurgency, revolution, guerrilla warfare, and civil war.

Foreign infiltration or liberation occurs when a government is overthrown by foreign military or diplomatic intervention, or through covert means. The campaign's ultimate purpose is to gain control over another nation's political and social structure. The campaign could be led by the aggressor's national forces or by a political faction favorable to the aggressor within the other state. Paul W. Blackstock describes three stages involved in the extension of control by the aggressor over the victim:
Penetration or infiltration: the deliberate infiltration of political and social groups within a victim state by the aggressor with the ultimate purpose of extending influence and control. The aggressor conceals its endgame, which goes beyond the normal influential nature of diplomacy and involves espionage.
Forced disintegration or atomization: "is the breakdown of the political and social structure of the victim until the fabric of national morale disintegrates and the state is unable to resist further intervention". The aggressor may exploit the inevitable internal tensions between political, class, ethnic, religious, racial, and other groups. This concept is a similar strategy to 'divide and conquer'.
Subversion and defection: Subversion is the "undermining or detachment of the loyalties of significant political and social groups within the victimized state, and their transference to the political or ideological causes of the aggressor". In lieu of total and direct transference, the aggressor may accept intermediate states that still meets its objectives, such as the favor of politically significant individuals. Furthermore, the formation of a counter-elite, made up of influential individuals and key leaders, within the victim state establishes the legitimacy and permanency of a new regime. Defection is the transference of allegiance of key individuals and leaders to the aggressor's camp. The individual could relocate or stay-in-place in the victim country, continually influencing local issues and events in the aggressor's favor. Defectors also provide insider information to the aggressor.
Coup d'état is the overthrowing of a government through the infiltration of the political, military, and social groups by a small segment of the state apparatus. The small segment exists within the state and targets the critical political levers of power within a government to neutralize opposition to the coup and post-coup governing force. Several pre-existing factors are necessary for a coup: political participation being limited to a small portion of the population, independence from foreign power influence and control, and power and decision-making authority concentrated within a political center and not diffused between regional authorities, businesses, or other groups.
A coup utilizes political resources to gain support within the existing state and neutralize or immobilize those who are capable of rallying against the coup. A successful coup occurs rapidly and after taking over the government, stabilizes the situation by controlling communications and mobility. Furthermore, a new government must gain acceptance from the public and military and administrative structures, by reducing the sense of insecurity. Ultimately, the new government will seek legitimacy in the eyes of its own people as well as seek foreign recognition. The coup d'état can be led by national forces or involve foreign influence, similar to foreign liberation or infiltration.

Paramilitary Operations: transitional political warfare ranging from small-scale use of violence with primitive organizational structure (e.g. sabotage) to full-scale conventional war. The transition and escalation includes a series of stages and depends on tactical and strategic objectives. Paramilitary activities include infiltration and subversion as well as small group operations, insurrection, and civil war.
Insurgency: an organized, protracted political warfare tool designed to weaken the control and eliminate the legitimacy of an established government, occupying power, or other political authority. An insurgency is an internal conflict, and the primary struggle is to mobilize local populations for political control and gain popular support towards the insurgents' cause. Insurgencies include political and military objectives, with the end goal of establishing a legitimate, rival state structure. Insurgencies are unconventional military conflicts which incorporate a variety of methods, ranging from coercive tools like intimidation and assassination, to political tools like propaganda and social services. An insurgency's approaches and objectives could involve perpetual disorder and violence demonstrating the government's inability to provide security for the populace, weakening the government and killing or intimidating any effective opposition against the government, intimidating the population and discouraging its participation in – or support for – political or legal processes, controlling or intimidating police and military forces (which limits their ability to respond to insurgent attacks) or by creating government repression by provoking over-reactions by security or military forces.

In antiquity: The history of political warfare can be traced to antiquity. The Chinese general and strategist Sun Tzu captures its essence in the ancient Chinese military strategy book, The Art of War: "So to win a hundred victories in a hundred battles is not the highest excellence; the highest excellence is to subdue the enemy's army without fighting at all...The expert in using the military subdues the enemy's forces without going to battle, takes the enemy's walled cities without launching an attack, and crushes the enemy's state without protracted war."
There are abundant examples of political warfare in antiquity. In ancient Greece, a famous example is that of the Trojan Horse, which used deception for tactical military objectives. Propaganda was commonly utilized, including Greek rhetoric and theatre which used words and images to influence populations throughout the Hellenic world. This practice has left a lasting legacy of speech as a mechanism of political power, greater than force in solving disputes and inducing submission. During this same period, Alexander the Great used coinage imprinted with his own image, indirectly forcing conquered nations to accept his legitimacy as national ruler and to unite disparate nations together under his dominion.
Ancient Rome utilized similar political warfare as the Greeks including rhetoric, as displayed by Cicero; and art, as seen in coinage, statues, architecture, engineering, and mosaics. All of these elements were intended to portray Rome's imperial dominance over its subject nations and the superior nature of Roman society. Following a religious vision, the emperor Constantine I in 330 CE bound the Roman state to the universal Christian Church. In doing so, he linked "religious commitment with imperial ambition" that proved to be quite successful and powerful.