美国已开放的档案中，有多份接触联络孙立人的报告。但若依据张淑雅、林博文
所述，目前可能尚有部份孙立人的相关档案仍未解密，因此密函可能是销毁了，
也可能有朝一日被发掘出来。
小弟把关于美国策划支持孙立人进行政变的档案段落贴上来，出处为：
Top Secret, 1950 Formosa And Hainan islands (Jan-Jul), CA Records,
Archives Unbound, pp. 164-165.
档案图文 Google文件 - https://goo.gl/70EZiX
档案影像 - http://imgur.com/a/BYqqj
6. Procedures to implement decision, if made, to insure re-
tention of Formosa in non-Communist hands.
(a) Confidential Declaration to Chiang Kai-shek, K. C. Wu
and Sun Li-jen.
It is not believed that the course of action suggested here
is desirable or that it would be in the U.S. national interest.
So long as the Generalissimo and his group of followers remain on
Formosa, they will be a source of embarrassment and trouble to
the U.S. By experience we know that they will be ready enough
with promises of action desired by the U.S. and equally ready
to fail in fulfillment of such promises. They will inevitably
look upon the course of events as providing them another oppor-
tunity of returning to power on the mainland and their efforts
will be directed chiefly to that end, even to the extent of
doing everything in their power to bring about a third world
war. For these reasons, it seems logical that the U.S. should
adopt one of two courses:
(1) It should make clear to the Generalissimo, K. C. Wu,
Chen Cheng and Sun Li-jen that the U.S. must insist upon the
cessation of hostilities between Formosa and the mainland; that
the U.S. will assist the provincial government in its adminis-
trative and economic tasks; that as a condition for U.S. economic
aid and military advice and assistance the Generalissimo and the
present group of leaders of the National Government must be
willing to leave the Island and turn over the civil and military
administration to such Chinese and Formosan leaders as the U.S.
may designate; that the U.S. will then give military advice and
assistance to the commander responsible for the defense of the
Island; that the U.S. will expect the provincial administration
on Formosa to give high priority to the welfares of the Formosan
people; and that the U.S. will order units of its navy to visit
Formosa in order to prevent action by against Formosa for a
period during which the problem of Formosa would be made the sub-
jest of discussion with other concerned governments.
(2) The U.S. should inform Sun Li-jen in the strictest
confidence through a private emissary that the U.S. Government is
prepared to furnish him the necessary military aid and advice in
the event that he wishes to stage a coup d'etat for the purpose
of establishing his military control over the Island. Sun should
also be given ample funds (the total might run into several mil-
lion dollars) to assist him in buying over the other commanders
necessary to such an undertaking; he should be given firm
assurances of whatever additional funds he might need in this
connection during the early stages. Urgent preparations would
have to be made to arrange for the shipment from Guam or some
other nearby U.S. base of the arms and ammunition necessary to
meet Sun's military requirements at the outset of such an under-
taking.
参考资料：
张淑雅。韩战救台湾？解读美国对台政策。页74-75、326-327。
林博文。1949石破天惊的一年。页133-153。
黄美华。美国对华政策之研究(1947-1950)。页166-174、238-243。
云程编。福尔摩沙‧1949。页299-301、327-328。