Great Britain

Great Britain uses a unitary government along with an unwritten constitution in their political system. Instead of the unitary leader, monarch, ruling, the bicameral parliament holds the legislative and executive powers. Most of this power is centered in the popularly elected House of Commons. In addition to the House of Commons, the House of Lords do have a little authority, although its nine law lords do have judicial junctions. In the government, the prime minister and cabinet are members of Parliament who are chosen by Parliament. The majority party in Parliament receives the honor of having some of its members acquire these positions. If at any time, the Prime Minister loses the support of Parliament, his or her administration falls. This leads to an election replacing the people in their government.
Japan
Ever since the 1800s the Japan political system, more western and democratic forms of government have emerged. Although throughout its history centuries ago, Japan was a feudal society. After World War II, Japan adopted their constitution of 1947 written largely at the direction of American occupation. Within this constitution is a unique antimilitary provision. The Diet, the elected national legislature, is bicameral. Most of the legislative powers in Japan lie in the House of Representatives. The other house in their bicameral government, the House of Councilors has little authority. From the coalition, the majority party, the Prime Minister and cabinet are obligated. These officials are chosen by and are responsible to the House of Representatives. Working with Japanese industry to coordinate policy, Japan's bureaucracy holds a unique position of prestige and power.
Mexico
Even though the Spanish colonization set up their government before Mexico earned its independence, the Aztec Empire had an advanced civilization that existed until their destruction by the Spanish. Mexican independence came in 1821. Now, the Constitution of 1917 is the base of Mexican government. The government has been controlled by one party, the Institutional Revolutionary Party (PRI), for years. Even though it has a democratic format, the Institutional Revolutionary Party has had control for more than 60 years. Mexico does have a president, but he or she can only serve for one six-year term. Despite only having one term, the President can handpick a successor. Their legislature is bicameral, but neither house is very powerful. The judiciary is independent and shares many of the same features of the U.S. court system. Being a federal government, the state and local government have considerable independence.
The Former Soviet Union
For more than 70 years the Soviet government was a dictatorship. Since 1985 it has undergone and ongoing changes. A failed coup in the summer of 1991 intruded an element of crisis and uncertainty that makes their government very unstable and predictable. The Soviet constitution was similar in form to Western-style constitutions before the coup. Sometime after the coup, a new Soviet constitution is anticipated to be instituted. Soviet government had been moving toward democracy at a steady pace with Gorbachev. January 1992, a Commonwealth of Independent States broke up the Union and sent the government into a great downfall. Remaining in question is the form of any future permanent government and the Soviet Union itself.