The aim is to be a smallish alliance of competent and somewhat evil-minded players, with a view to getting involved in some games against other alliances and (ideally) slaughtering the opposition.
Something I nicked from Wiki about SPECTRE below. Note Blofeld's thoughts on Siamese fighting fish which are, I think, very apposite.
Philosophy and goals
Blofeld's SPECTRE volcano base complete with stolen Soviet rocket shuttle, helipad and attack helicopter, and command center in the 1967 film You Only Live Twice. The world map in the background is common to emphasize the aim of world domination.
In Ian Fleming's novels, SPECTRE is a commercial enterprise led by Blofeld. Their membership comprises 18 individuals, three each from the world's six great criminal organizations—the Gestapo, SMERSH, Marshal Tito's secret police, the highland Turks, the Mafia, and the Unione Corse. Their debut is in Thunderball. At the time of writing the novel (1959) Fleming believed that the Cold War might end during the two years it would take to produce the film, which would leave it looking dated; he therefore thought it better to create a politically neutral enemy for Bond. The organization is next mentioned in The Spy Who Loved Me, when Bond describes investigating their activities in Toronto before the story begins.
The organization's third appearance is in On Her Majesty's Secret Service where Blofeld, hired by an unnamed country or party (though the Soviet Union is implied) is executing a plan to ruin British agriculture. Blofeld, without SPECTRE would appear for the final time in You Only Live Twice.
In the films, the organization has a more active role, often as a third party in the ongoing Cold War. Its basic strategy is illustrated by the analogy of the three Siamese fighting fish Blofeld keeps in an aquarium in the film version of From Russia with Love. Blofeld notes that one fish is refraining from fighting two others until their fight is concluded. Then, that cunning fish attacks the weakened victor and kills it easily. Thus SPECTRE's main strategy is to instigate conflict between two powerful enemies, namely the superpowers, hoping that they will exhaust themselves and be vulnerable when SPECTRE finally moves in to seize power.
It should be noted that the goal of world domination was only ever stated in You Only Live Twice, and that SPECTRE was working not for itself but for an unnamed Asian government whose two representatives Blofeld speaks to during the movie. This is likely North Korea or Red China, who in the third film were the backers of Goldfinger. SPECTRE's goals in the other films it has appeared in have always been less lofty.
In both the film and the novel Thunderball, the physical headquarters of the organization are laid in Paris, operating behind the front of an international organization aiding refugees (Firco in the novels; International Brotherhood for the Assistance of Stateless Persons in the films).
Organizational discipline is notoriously draconian with the penalty for disobedience or failure being death. As quoted by Blofeld on several occasions: "This organization does not tolerate failure". Furthermore, to heighten the impact of the executions, Blofeld often chooses to focus attention on an innocent member, making it appear his death is imminent, only to suddenly strike down the actual target when that person is off guard.
Fleming's SPECTRE has elements inspired by mafia syndicates and organized crime rings that were actively hunted by law enforcement in the 1950s. The strict codes of loyalty and silence, and the hard retributions that followed violations, were hallmarks of U.S. gangster rings, Mafia, the Unione Corse, the Chinese Tongs/Triads and the Japanese Yakuza/Black Dragon Society.
SPECTRE is headed by the supervillain, Ernst Stavro Blofeld who usually appears accompanied by a white Persian cat in the movies, but not in the books. In both the films and the novels, Emilio Largo is the second in command. It is stated in the novel that if something were to happen to Blofeld, Largo would assume command. Largo appears for the first and only time in Thunderball and also in the unofficial James Bond film Never Say Never Again.
In the novels, the numbers of members were initially assigned at random and then rotated by two digits every month to prevent detection. For example, if one was Number 1 this month, he would be Number 3 next month. At the time of Thunderball, the leader, Ernst Stavro Blofeld, has been assigned "Number 2", while Emilio Largo is assigned "Number 1". In the films the number indicates rank: Blofeld is always referred to as "Number 1" and Emilio Largo, in Thunderball, is "Number 2".
The SPECTRE cabinet had a total of 21 members. Blofeld was the chairman and leader because he founded the organisation and Largo was elected by the cabinet to be second in command.
This particular example of numbering is perhaps deliberately borrowed from revolutionary organisations, wherein members exist in cells, and are numerically defined to prevent identification and cross-betrayal of aims. By deliberately drawing attention away from the true leader of the organisation, he is protected by masquerading as a target of lower importance, and the structure of the organisation is also obscured from intelligence services.