Switzerland, despite hosting the UN's European headquarters and many UN agencies in Geneva for decades, became a full member state of the United Nations only in which year?

The correct answer is 2002. Switzerland formally became the 190th member state of the United Nations on 10 September 2002, following a national referendum held earlier that year in which a majority of Swiss voters approved joining the organisation. This came remarkably late compared to most European states, largely because Switzerland's deeply rooted policy of neutrality led earlier generations of Swiss voters and policymakers to resist full UN membership, fearing it might compromise the country's neutral status, particularly regarding potential obligations under collective security provisions. Despite this delayed membership, Geneva had already served as the UN's European headquarters and home to major agencies such as the World Health Organization and the International Labour Organization for decades prior. The distractor '1945' is incorrect because that year marks the UN's founding at the San Francisco Conference, when Switzerland was notably absent from the original 51 member states due to its neutrality concerns. '1975' is wrong because no such accession occurred that year; Switzerland remained outside full UN membership throughout the mid-to-late twentieth century. '1990' is incorrect for the same reason, as Switzerland's eventual UN referendum and accession occurred over a decade later, in 2002. A common exam confusion arises when candidates assume that hosting UN institutions automatically implies membership; Switzerland's case sharply illustrates that a country can be a major host nation for international bodies while remaining outside formal membership for an extended period due to specific political considerations like neutrality. The revision takeaway: fix 2002 firmly as Switzerland's UN accession year, following a referendum, and remember this was driven by concerns over neutrality rather than any earlier historical event — one of the more distinctive chronology facts in world organisation-related GK questions.