In June 1965, Britain, in consultation with Belize, agreed with Guatemala to submit the dispute to a Mediator appointed by the United States Government. The Mediator, Mr. Bethuel M. Webster
The mediator submitted the Webster Proposal…
The plan placed the defence, foreign affairs and, to a certain extent, the economy of Belize under Guatemalan control after independence. The normal channel of communication to international bodies by the Belize government was to be through the Guatemalan government.
In sum, it is believed that the proposals exclusively committed Belize to a hemispheric destiny as a satellite or department of Guatemala. Nowhere in the document was it stated that the Guatemalan claim was revoked. Nor was Belize explicitly given the right to seek membership of the Commonwealth, the United Nations or international bodies outside of the Inter-American system. She was, in short, denied the prerogative of an independent state to choose, or reorder at least some of the priorities of her future.
Bearing in mind the great disparity between Guatemala and Belize in terms of population and resources, the end result, of these proposals, taken together, would have been the effective domination of Belize by Guatemala. Belize accordingly, declared that these proposals were totally unacceptable.