Although the controversy between president and field commander played out within the context of the Korean War, Pearlman explains that "the roots of the Korean War conflict between Truman and MacArthur lay outside Korea," namely in China, recently "lost" to Mao Zedong's communists to the great embarrassment of the Truman administration. The book notes that "policy debates created partisan squabbles that inflamed policy debates about who was responsible for the communist victory on the mainland and what was to be done about Formosa, known as Taiwan to the Chinese." MacArthur considered Taiwan and Chiang Kai-shek's Kuomintang party Nationalists who had fled there after losing to Mao on the mainland the key to a successful U. S. Asian policy, a position that aligned him with the Truman administration's most ardent Republican opponents. While "by mid-1950, [MacArthur] had convinced the Department of Defense that Formosa was vital to U. S. security … the State Department had other opinions." Secretary of State Dean Acheson, "whom Truman called his 'number-one brain man'" (and who, like Truman, despised MacArthur), approached the issue in more pragmatic, less ideological terms, hoping that Mao, although a Marxist, might eventually turn against Moscow (like Yugoslavia's Tito had done in 1948). At any rate, Europe was Acheson's and the administration's main concern, while MacArthur had long before cast his lot with Asia as "the place he thought destined to determine global supremacy" and Formosa the location he was convinced would "shape great events in Asia." Backing Chiang and involving the U. S. in defending his sanctuary on Taiwan, according to Acheson, risked war with China (as did getting too close to the Manchurian border in Korea, a fear that caused the Secretary of State to make a rare intervention in MacArthur's battlefield decisions by convincing Truman to insist that only South Korean forces approach the Yalu river border in the autumn of 1950 – in retrospect a futile gesture, since the Chinese began to intervene much earlier, right after Truman had sent MacArthur's forces north across the 38th parallel in October 1950). For his stance on Taiwan (and for his support of containing – not rolling back — communist global gains), Acheson was branded "soft on communism" by Truman's Republican opponents. MacArthur's pro-Taiwan statements, therefore, provided the Republicans with headline-grabbing ammunition to use against Acheson, further infuriating Truman.
"The central issue in the story has long been known," Pearlman notes, "the general would attack China; the president would not" and MacArthur made his views well known. Truman backed his "number-one brain man" on the China-Taiwan policy issue (although Acheson and Truman later came around to supporting Taiwan), and became livid each time MacArthur made his pro-Taiwan views public. The China-Taiwan policy issue, Pearlman asserts, not MacArthur's battlefield actions on the Korean peninsula, was the real flash point between the Truman administration and the general: "the issue, crackling through the conflict, was a major factor in the dismissal of MacArthur," Pearlman reveals. Yet, had the president ever lived up to his own "tough guy" image of himself and given the general a personal, direct order not to make public statements about policy issues, MacArthur would have obeyed (in letter if, perhaps, not in spirit), but such a direct order from the president never came – the famous December 6, 1950 "gag order" sent by the Joint Chiefs of Staff to all military commands, not just MacArthur's headquarters, was a weak, mealy-mouthed directive with too much wiggle room to permanently silence a military icon as strong willed and so used to being allowed to have his own way as MacArthur. Pearlman judges "the president needed to foreclose all ambiguity by issuing detailed directives with crystal clear clarity. The so-called gag order, not really a direct order at all, hardly met this standard…If [Truman] had been firm, resolute, and clear to MacArthur from 1950, not to mention 1945, there might have been no need for drastic action in 1951."
Yet, the "drastic action" of April 11, 1951 still might never have occurred had not MacArthur, in Truman's assessment, crossed the line from policy disagreement into the realm of partisan politics.