As defined by the World Tourism Organization (WTO), tourism comprises the activities of persons travelling to and staying in places outside their usual environment for not more than one consecutive year for leisure, business, and other purposes. Key concepts of sustainable development and sustainable tourism, values and ethics of sustainable tourism and the needs of sustainability in all form of tourism shall be discussed in this essay. 2.1 Sustainable Tourism
Since World War II, tourism has developed from a relatively minor activity to the world's largest industry. The travelling within more developed countries as well as from more developed countries to less developed countries generally increased. It also consists of the majority of middle classes travelling among less developed countries but also to the more developed countries. The term sustainable tourism emerged from a broader discourse on the idea of sustainable development (Bramwell and Lane, 1993). It aims to obtain economic, socio-cultural and environmental benefits and helping to conserve the environment. Tourism which is developed and maintained in an area (community, environment) in such a manner and at such a scale that it remains viable over an indefinite period and does not degrade or alter the environment (human and physical) in which it exist to such a degree that it prohibits the successful development and well-being of other activities and processes (Butler 1993 in Wahab and Pigram 1997, p44). According to Jafari, the global tourism sector has been influenced and described by a few model platforms, 'advocacy', 'cautionary', 'adaptancy' and 'knowledge-based' platforms. At the later stage, Macbeth (2005) rethought the model and proposed the other 2 models, 'sustainable' and 'value full' platforms. These distinct perspectives provide a useful structure for understanding the outgrowth and development of sustainable tourism. However these platforms do not represent a pure type or ideology but rather be used for understanding for stakeholders on tourism and it is not mutually exclusive. 2.1.1 Advocacy platform
The advocacy platform was the first to appear in the post-war period during the 1950s to 1960s and was characterized by the strong support for tourism. There were a few factors leading to the appearance and ascendancy of this pro-tourism. The tendency to travel for recreational purposes of the middle class in the more developed countries grew after World War II. The cost of travel was reduced and the accessibility to more destinations was opened to a larger market. Less developed countries was made favorable to economic development judging the inexhaustible supply of resources such as the local culture, scenery and beaches. Economic benefits
Tourism generates direct revenues as well as indirect revenues to the country. In this case it creates a large number of employments to the direct or indirect sectors for the unskilled labor force. It also serves as a generator of infrastructure. Socio-cultural and environment benefits
Tourism promotes cross-cultural understanding and, ultimately, world peace, through direct contact between host and guest (D'Amore, 1988). It also provides an incentive to conserve the tradition, natural and man-made environment. The iconic heritage sites such as the Great Wall of China, Egyptian pyramids of Giza and Machu Picchu of Peru would seriously be the tourism attraction of the countries. Therefore a portion of the revenue can be allocated for maintenance or restoration purposes. 2.1.2 Cautionary platform
Cautionary platform was emerged in the late 1960s to 1970s due to several factors contributing it. It has been argued that unrelated tourism development ultimately rises in unacceptably high economic, environmental and socio-cultural cost for the locals of the destinations, who are losing out as a result of these costs. For less developed countries, the intensification of tourism development had been...