As a political and military alliance, what we do together at NATO directly contributes to the security, the prosperity, and liberty of the people of the United States and every Ally.Our NATO links are solid, forged over 70 years of history. NATO promotes democratic values and encourages consultation and cooperation on defense and security issues to build trust and, in the long run, prevent conflict. NATO is committed to the peaceful resolution of disputes. If diplomatic efforts fail, it has the military capacity needed to undertake crisis-management operations. These are carried out under Article 5 of the Washington Treaty — NATO’s founding treaty — or under a UN mandate, alone or in cooperation with other countries and international organizations. In the history of NATO, Article 5 has been invoked just once, and that was in response to the 9/11 terrorist attacks in the United States.