The US petitioned the international community to back a military campaign to overthrow the Taliban. The UN issued two resolutions on terrorism after the 11 September attacks. The resolutions called on all states to "[increase] cooperation and full implementation of the relevant international conventions relating to terrorism" and specified consensus recommendations for all countries. According to a research briefing by the House of Commons Library, although the United Nations Security Council (UNSC) did not authorise the US-led military campaign, it was "widely (although not universally) perceived to be a legitimate form of self-defense under the UN Charter", and the council "moved quickly to authorize a military operation to stabilize the country" in the wake of the invasion. Moreover, on 12 September 2001, NATO approved a campaign against Afghanistan as self-defense against armed attack.