158 PROMOTING AND PROTECTING MINORITY RIGHTS ARTICLE 1 1.1 States shall protect the existence and the national or ethnic, cultural, religious and  linguistic identity of minorities within their respective territories and shall encourage conditions for the promotion of that identity. 21. The relationship between the State and its minorities has in the past taken five different forms: elimination, assimilation, toleration, protection and promotion. Under present international law, elimination is clearly illegal. The Declaration is based on the consideration that forced assimilation is unacceptable. While a degree of integration is required in every national society in order to make it possible for the State to respect and ensure human rights to every person within its territory without discrimination, the protection of minorities is intended to ensure that integration does not become unwanted assimilation or undermine the group identity of persons living on the territory of the State. 22. Integration differs from assimilation in that while it develops and maintains a common domain where equal treatment and a common rule of law prevail, it also allows for pluralism. The areas of pluralism covered by the Declaration are culture, language and religion. 23. Minority protection is based on four requirements: protection of the existence, non‑exclusion, non-discrimination and non-assimilation of the groups concerned. 24. The protection of the existence of minorities includes their physical existence, their continued existence on the territories on which they live and their continued access to the material resources required to continue their existence on those territories. The minorities shall neither be physically excluded from the territory nor be excluded from access to the resources required for their livelihood. The right to existence in its physical sense is sustained by the Convention on the Prevention and Punishment of the Crime of Genocide, which codified customary law in 1948. Forced population transfers intended to move persons belonging to minorities away from the territory on which they live, or with that effect, would constitute serious breaches of contemporary international standards, including the Rome Statute of the International Criminal Court. But protection of their existence goes beyond the duty not to destroy or deliberately weaken minority groups. It also requires respect for and protection of their religious and cultural heritage, essential to their group identity, including buildings and sites such as libraries, churches, mosques, temples and synagogues. 25. The second requirement is that minorities shall not be excluded from the national society. Apartheid was the extreme version of exclusion of different groups from equal participation in the national society as a whole. The Declaration on Minorities repeatedly underlines the rights of all groups, small as well as large, to participate effectively in society (arts. 2.2 and 2.3). 26. The third requirement is non-discrimination, which is a general principle of human rights law and elaborated by, inter alia, the International Convention on the Elimination of All Forms of Racial Discrimination, which also covers discrimination on ethnic grounds. The Declaration on Minorities elaborates the principle of non-discrimination in its provision that the exercise of their rights as persons belonging to minorities shall not justify any discrimination in any other field, and that no disadvantage shall result from the exercise or non-exercise of these rights (art. 3). 27. The fourth requirement is non-assimilation and its corollary, which is to protect and promote conditions for the group identity of minorities. Many recent international instruments use the term “identity”, which expresses a clear trend towards the protection and promotion of cultural diversity, both internationally and internally within States. Relevant provisions are articles 29 and 30 of the Convention on the Rights of the Child, article 31 of the International Convention on the Protection of the Rights of All Migrant Workers and Members of Their Families, article 2.2 (b) of