Solomon Islands governments are characterized by weak political parties (see List of political parties in Solomon Islands) and highly unstable parliamentary coalitions. They are subject to frequent votes of no confidence, and government leadership changes frequently as a result. Cabinet changes are common.Land ownership is reserved for Solomon Islanders. The law provides that resident expatriates, such as the Chinese and Kiribati, may obtain citizenship through naturalization. Land generally is still held on a family or village basis and may be handed down from mother or father according to local custom. The islanders are reluctant to provide land for nontraditional economic undertakings, and this has resulted in continual disputes over land ownership. No military forces are maintained by the Solomon Islands, although a police force of nearly 500 includes a border protection unit. The police also are responsible for fire service, disaster relief, and maritime surveillance. The police force is headed by a commissioner, appointed by the governor-general and responsible to the prime minister. On 27 December 2006, the Solomon Islands Government said it had taken steps to prevent the country's Australian police chief from returning to the Pacific nation. On 12 January 2007, Australia replaced its top diplomat expelled from the Solomon Islands for political interference in a conciliatory move aimed at easing a four-month dispute between the two countries. On 11 July 2007, the Solomon Islands swore in Julian Moti as their Attorney General. Moti is currently wanted in Australia for child-related sex offences. Australian Prime Minister John Howard called the move "quite extraordinary". Australia's Foreign Minister Alexander Downer has described the country as the "laughing stock" of the civilised world.22 - However the Australian charges against Moti relate to events in Vanuatu, and parallel charges which the courts in Vanuatu dismissed in the 1990s. Julian Moti has attracted Australian attention because he advised the Solomons Government to inquire into the role of Australian police in provoking the 2006 Honiara riots. On 13 December 2007, Prime Minister Manasseh Sogavare was toppled by a vote of no confidence in Parliament,23 - following the defection of five Ministers to the Opposition. It was the first time a Prime Minister lost office in this way in the Solomon Islands. On 20 December, Parliament elected the Opposition's candidate (and former Minister for Education) Derek Sikua as Prime Minister, with 32 votes to 15.24 - 25 -