List of treaties in Star Trek
Treaty of Algeron 
The Treaty of Algeron is an agreement signed by the United Federation of Planets and the Romulan Star Empire in 2311, following the Tomed Incident. David R. George III's novel Serpents Among the Ruins (2003) depicts the subterfuge that leads to the Tomed Incident and subsequent treaty. The treaty reaffirmed the neutral zone between the Romulan Empire and Federation, violation of which constitutes an act of war. The treaty also forbids the Federation from developing a cloaking device. Prior to the Dominion War, the Romulans loaned Starfleet a cloaking device for use in the Gamma Quadrant.
Khitomer Accords 
The Khitomer Accords comprised two treaties, the first of which was set down between the Klingon Empire and the Federation in 2293, the beginning of peace between the two former adversaries. Chancellor Gowron (Robert O'Reilly) withdrew the Klingons from the original agreement during their invasion of Cardassia in Deep Space Nine's fourth season. But he reinstated them the following season, thus making the treaty the Second Khitomer Accords, when the Dominion threatened the Alpha Quadrant.
Organian Peace Treaty 
The Organian Peace Treaty is an armistice imposed by the Organians upon the Federation and the Klingon Empire in "Errand of Mercy" (1967). It is an example of the pacifist moral tone the show created at the time of the Vietnam war. The treaty stops a potential war between the Federation and Klingon Empire, and establishes that disputed planets should be awarded to the power that can develop the planet most efficiently. Such a planetary dispute occurs in "The Trouble With Tribbles" (1967). The impact of the Organian Peace Treaty on the politics of the Klingon Empire are described in the Blood will Tell comic series; other Star Trek Expanded Universe literature explores the Organians' apparent disappearance from galactic events.
The Treaty of Armens 
Established in 2255 between the Sheliak Corporate and the United Federation of Planets, the Treaty of Armens contained 500,000 words and took 372 Federation legal experts to draft.