Treaty of Alliance The Treaty of Alliance ( also known as the Klingon Alliance ) was the official agreement that established the alliance between the United Federation of Planets and the Klingon Empire . Vulcan Ambassador Sarek was one of the key figures behind the negotiations that created the alliance , and his son , Ambassador Spock , was the one who proposed the alliance . ( ; ) The Treaty was regarded with controversy when first suggested , but later proved to be a cornerstone for peace in the Alpha Quadrant . The Federation - Klingon alliance represented a fundamental shift in the balance of power in the Alpha and Beta Quadrant s , as the two former enemies united . According to the treaty ' s terms , each side could request the other ' s assistance in fighting against its enemies . This clause , in part , forced the Romulan Star Empire to the sidelines , unable to compete against the combined forces of the Federation and the Klingons . As a result , the Romulans devoted considerable resources towards trying to break up the alliance , albeit without success . ( ) This part of the Treaty , however , did not permit interference in the internal affairs of the signatories . Then - new Klingon Chancellor Gowron requested Federation assistance in the Klingon Civil War of 2368 per the treaty , but the request was declined as it was an internal conflict . ( ) The Treaty allowed the Federation to conduct health and safety inspection s of Klingon vessels within Federation space . It also allowed for unrestricted travel by each side in the other ' s space . ( ) In 2372 , the Dominion was able to break the alliance by manipulating the Klingon Empire into an unprovoked invasion of the Cardassian Union , an action condemned by the Federation . The alliance was resumed the following year , after the Dominion joined the Cardassian s ' war against the Klingons . ( ) During the Dominion War , the Dominion worked with the Orion Syndicate on another way to break the alliance . By using Klingon weapons to assassinate an anti - Federation ambassador on Farius Prime , it was hoped Gowron would be implicated and the Klingon people would call for the alliance to end . Fortunately , operatives of Starfleet Intelligence intercepted the plan and alerted the Klingons in time to prevent the assassination . ( ) Background information . The Treaty of Alliance may have been signed around the same time as the Second Khitomer Accords which were mentioned in . Various DS9 episodes seemed to equate the Khitomer Accords with the Treaty of Alliance , implying they were connected in some way . It is unclear when exactly The Treaty of Alliance was signed , however it must have occurred after 2327 , per dialog in ( date established in ) . In 2344 , Klingon - Federation relations improved after the attempted to save a Klingon outpost on Narendra III during a Romulan attack on it . ( ) In , William T . Riker said that he learned about the career of Sarek at school and also mentioned the Klingon Alliance as one of Sarek ` s achievements . Riker entered Starfleet Academy in 2353 ; since Starfleet Academy typically took four years to complete , the Treaty of Alliance must have taken place some time prior to his graduation in 2357 . So , if it was signed in the 24th century , as is most likely , it could have happened between 2344 and 2357 . According to dialogue in , the events of that episode saw an end to " two decades of peace with the Klingons . " Assuming that line is taken literally , that would place the signing of the treaty at 2352 , which falls within the above figured timeframe .