now called Thailand. Siam is the key to the game (of Risk). this is said because whoever controls Siam controls access to the continent of Australia, and holding said continent allows you to have a practically unassailable home base to attack from.
Thai kingdom, now called Thailand.
a country of southeastern Asia that extends southward along the Isthmus of Kra to the Malay peninsula; "Thailand is the official name of the former Siam"