saudi arabia joined the un in 1945 and is a founding member of the arab league, gulf cooperation council, muslim world league, and the organization of the islamic conference (now the organisation of islamic cooperation). it plays a prominent role in the international monetary fund and the world bank, and in 2005 joined the world trade organization. saudi arabia supports the intended formation of the arab customs union in 2015 and an arab common market by 2020, as announced at the 2009 arab league summit.