随便今天发帖说“美国军队四星上将总数不得超过18名，退休后只能保持两星”。

两点都是错误的。

实际是，美军各军种现役上将总数加起来为38名（见：List of active duty United States four-star officers）

随便18这个数字想必是根据其所引用的维基条目掰手指数出来的“。。。This is set at 7 four-star Army generals,[2] 9 four-star Air Force generals[2] and 2 four-star Marine generals.[2]”（见随便：“美国军队四星上将总数不得超过18名，退休后只能保持两星”）

讲句公道话，随便同学手指倒没有掰错，错在不认真，没有动脑筋细究，被维基这条写得灰强不严谨的条目坑了一把。

根据维基该条目提供的索引，美国法律规定的上将总数应该是：

(a) For purposes of the applicable limitation in section 526 (a) of this title on general and flag officers on active duty, no appointment of an officer on the active duty list may be made as follows:
(1) in the Army, if that appointment would result in more than—
(A) 7 officers in the grade of general;
(B) 45 officers in a grade above the grade of major general; or
(C) 90 officers in the grade of major general;
(2) in the Air Force, if that appointment would result in more than—
(A) 9 officers in the grade of general;
(B) 43 officers in a grade above the grade of major general; or
(C) 73 officers in the grade of major general;
(3) in the Navy, if that appointment would result in more than—
(A) 6 officers in the grade of admiral;
(B) 32 officers in a grade above the grade of rear admiral; or
(C) 50 officers in the grade of rear admiral;
(4) in the Marine Corps, if that appointment would result in more than—
(A) 2 officers in the grade of general;
(B) 15 officers in a grade above the grade of major general; or
(C) 22 officers in the grade of major general.

（见：10 USC § 525 - Distribution of commissioned officers on active duty in general officer and flag officer grades）

共计：24。随便同学因引用的维基条目漏了海军的6个名额，故此错误地得出18。

另外，随便还没有看到，除了这24个名额，法律还给予国防部长相当的可自行裁夺的额外名额。

Exceptions to statutory limits：

There are several exceptions to the limits allowing more than allotted four-star officers within the statute. A four-star officer serving as Chairman [9] or Vice Chairman of the Joint Chiefs of Staff [9] does not count against his or her service's general or flag officer cap. An officer serving as Chief of the National Guard Bureau [5] does not count against his or her service's general officer cap. The Secretary of Defense can designate no more than 20 additional four-star officers,[4] who do not count against any service's general or flag officer limit,[4] to serve in one of several joint positions. These positions include the commander of a unified combatant command,[10] the commander of U.S. Forces Korea,[10] and the deputy commander of U.S. European Command [10] but only if the commander of that command is also the Supreme Allied Commander, Europe.[10] Officers serving in certain intelligence positions are not counted against statutory limit, including the Director of the Central Intelligence Agency.[11] The President may also add up to 5 four-star slots to one service if they are offset by removing an equivalent number from other services.[5] Finally, all statutory limits may be waived at the President's discretion during time of war or national emergency.[12]

（引自：List of active duty United States four-star officers。又见：10 USC § 526 - Authorized strength: general and flag officers on active duty）

正如本人一再提醒随便同学的，不是不能用古狗，但会古狗不等于会 research。两者是有本质区别的。

当然，本人今天下午因匆忙，一目十行，也把所有将级军衔的名额与上将名额混为一谈了。灰强粗心，也被维基那个写得极其糟糕的条目坑了一哈。

故此，同责。共勉。

喔，至于由“Historically, officers leaving four-star positions were allowed to revert to their permanent two-star ranks to mark time in lesser jobs until statutory retirement, but now such officers are expected to retire immediately to avoid obstructing the promotion flow.”这段英文，得出上将“退休后只能保持两星”，则纯粹是缺乏基本的英文阅读能力的问题了。

相信所有具基本英语能力的同学都可以自行判断。本人就不赘言解释了。