What was one of churchill's purposes for writing "the sinews of peace"? to reject and dismiss calls for the british government to forge a "special relationship" with the american government to call for the united states to establish formal diplomatic relations with the soviet union in order to prevent further war to warn america and the world about the threat that the soviet union and the rise of communism posed to freedom and peace to advocate for the united nations to develop its own armed forces so that member states need not participate in future wars