The question is, just what all-out aid means. If it means US troops, there is practically no chance of this. As dedicated an anti-Communist as General MacArthur repeatedly said, "anyone in favor of sending American ground troops to fight on Chinese soil should have his head examined."
https://books.google.com/books?id=462-ocjLNtAC&pg=PA76
Would anything short of this be enough? I doubt it. Chiang got plenty of aid from the US. Derk Bodde (an American professor who was a witness to the Communist takeover), describing the PLA victory parade in Beijing in 1949 said "what made it especially memorable to Americans was the fact that it was primarily a display of *American* military equipment, virtually all of it captured or obtained by bribe from Kuomintang forces in the short space of two and one half years."
https://archive.org/stream/pekingdiaryayear009614mbp#page/n133/mode/2up
Here let me anticipate two arguments: (1) The notion that Chiang was on the verge of a decisive victory in Manchuria in 1946 and was prevented from winning only by a cease-fire imposed by Marshall is not supported by the evidence. See *Harold M. Tanner. The Battle for Manchuria and the Fate of China: Siping, 1946* the concluson of which is summarized by one reviewer as follows: "The major question concerns the decisiveness of the battle of Siping. In retrospect, many Nationalists have looked on this battle as a lost chance to win the war. According to this view, the Nationalists had the Communists in full retreat until the Americans interfered with the cease-fire that halted pursuit of Mao’s armies. The pause allowed the Communists to rebuild their forces and eventually win control of Manchuria. Without a cease-fire, supporters of this argument believe that Nationalists would have secured control of Manchuria and eventually defeated the Communists across China. In response, Tanner argues that Siping did not set the stage for a possible Nationalist victory in Manchuria. Chiang’s armies faced logistical and manpower problems and that further advance might have fatally exposed Nationalist forces to Communist hit-and-run attacks."
http://www.h-net.org/reviews/showrev.php?id=39472 Another review (not available in full to non-subscribers): "Tanner systematically refutes such charges against Marshall...Using a variety of recently available archival materials, he demonstrates that leadership on both sides had military reasons for accepting the ceasefire at that time. In reality, Marshall's maneuvers were peripheral to their strategic decision making. The latter was shaped by perceptions of the changing facts on the battlefield. *Chiang had no intention at the time of pursuing the communists beyond the Songhua River.* [emphasis added]. Although Western and Taiwan-based historians have argued in hindsight that pursuing and annihalating the communists is what he should have done, Chiang was focused on consolidating his hold on southern Manchuria by moving north to capture Changchun. Tanner quotes Chiang's diary to make this point. As for Marshall, both the communist and nationalist leaders considered him a nuisance...to be humored and outmanuevered at the negotiating table... "
http://ahr.oxfordjournals.org/content/118/5/1500.extract The notion that Marshall prevented Chiang feom gaining a decisive victory by taking Harbin is also false: see my post at
https://groups.google.com/d/msg/soc.history.what-if/gRV99OKh4jc/hMSaSkGkCeQJ where I point out that "In short, the significance of this particular event seems to have been overblown. Marshall did not coerce a reluctant Chiang into losing a golden opportunity to wipe out Lin Biao's troops; rather, Chiang as well as Marshall was worried that going too far north could be provocative to Stalin, and anyway capturing Harbin would not have made that much of a difference, militarily speaking, for the KMT."
(2) 'What about the arms embargo imposed for eight months in connection with the Marshall mission?" Answer: "In military terms, however, the embargo's effect was limited, since the Nationalist forces had already been well equipped with surplus materiel from U.S. bases in the Pacific." Odd Arne Westad, *Decisive Encounters: The Chinese Civil War, 1946-1950* (Stanford University Press 2003), p. 49.
https://books.google.com/books?id=JBCOecRg5nEC&pg=PA49
"Overall, however, the KMT had ample supplies of weapons and probably lost more to capture, defection, and poor planning than to maintenance failure. A 1950 classified evaluation by the Nationalist Ministry of National Defense accurately assessed the issue: 'We have never heard it said that our military defeat in recent years resulted from a lack of ammunition or an insufficiency of other supplies. Rather, we inadequately understood bandit-suppression and anticommunism; we had insufficient morale; and our government, economy and programs completely failed to provide close support for the bandit-suppression military effort.' Jonathan M. House, *A Military History of the Cold War, 1944–1962* (University of Oklahoma Press 2012).
https://books.google.com/books?id=T5lxAwAAQBAJ&pg=PT144
BTW, as House notes, even during the arms embargo, the US "gave or sold China another $200 million worth of 'nonmilitary' wartime surplus trucks and other equipment, often at advantageous rates." Those who argue that the US didn't do enough to Chiang sometimes discount all aid that wasn't strictly "miitary" but this is absurd. The more such aid the KMT got--*if it was effective* (and the *effectiveness* of US aid, both military and economic is a different matter from its extent) the more it could devote to the war. Money, after all, is fungible. There may have been some spare parts the KMT could only get from the US but as noted they were hardly decisive.
