Bahá'ís are forbidden to join political parties, to accept partisan political office, to take part in political agitation, or to involve themselves in subversive activity, and are enjoined to loyalty and obedience to the government of the country in which they live. The rationale offered is that the faith's purpose is unity and that partisan alignment would fracture a worldwide community across national and ideological lines. Voting in elections is permitted where it can be done without party affiliation, and non-partisan public service is permitted. The rule's severity is best seen in Iran, where Bahá'ís have been executed, imprisoned, dispossessed and barred from education for four decades, and where the community has consistently declined to organise politically, has instructed its members not to participate in opposition movements, and has directed its response through international human rights bodies instead. Iranian authorities have nonetheless repeatedly charged Bahá'ís with espionage for Israel — a charge grounded in the location of the World Centre, which exists because the Ottomans exiled Bahá'u'lláh there.