linchpin
(en)
(noun) a locking pin inserted crosswise (as through the end of an axle or shaft) / (noun) one that serves to hold together parts or elements that exist or function as a unit
The Bretton Woods system, already set out in 1944, posited the dollar as the sole linchpin holding together the edifice of global trade and finance.
notable
6 years, 8 months ago