The Croatian parliament's powers are defined by the Constitution of Croatia. These include: defining economic, legal and political relations in the Republic of Croatia; preservation of Croatia's natural and cultural heritage and its utilisation; and forming alliances with other states. The parliament has the right to deploy Croatian armed forces abroad. It may also restrict constitutional rights and liberties in wartime or in cases of imminent war or following natural disasters, although that constitutional provision is limited to specific rights—right to life, prohibition of torture, cruel or denigrating conduct or punishment, upholding of habeas corpus and freedoms of thought, conscience and religious views. In addition, in those circumstances parliamentary members' terms may be extended. (As these rights are defined by the constitution, the decision would require a two-thirds majority. Since Croatia never declared a state of war during the breakup of Yugoslavia, this option has not been exercised in practice.) The parliament reserves the right to amend the borders of Croatia. The parliament decides on constitutional amendments, enacts legislation, passes the state budget, declares war and decides on the cessation of hostilities, adopts declarations of policy of the parliament, adopts national defence strategy, representing a long-term defence resource planning document, and national defence strategy, which defines bases for establishment and implementation of institutions, measures and activities in response to general security issues and specific challenges and threats to Croatia, implements civil supervision of the armed forces and security services, calls referenda, performs elections and appointments conforming to the constitution and applicable legislation, supervises operations of the government (headed by the Prime Minister of Croatia) and other civil services responsible to the parliament, grants amnesty for criminal offences and performs various other duties defined by the constitution. Becoming the Prime Minister of Croatia requires majority support in the parliament.