《希特勒傳》中希特勒所說的「1942年起美國就有條件介入二戰」的緣由？

01-07

喬西姆·費斯特（約阿希姆·費斯特）的《希特勒傳》其中有一段話（296頁最後一行）：
「1940年12月，希特勒似乎完全根據他的本性根據他的畢生計劃根據他目前對自己的過高估計做出了決定——儘快與蘇聯開戰······1940年12月17日,他對約德爾將軍詳細闡述了他對此次戰役的作戰思想,他在最後說：我們必須在1941年就解決歐洲大陸的所有問題,因為1942年起美國就有條件介入了.」
有些遊戲（鋼鐵雄心4）也提到過類似內容：美國的國家焦點中所謂的針對德國黑色計劃（以傀儡德國為目標對德宣戰）以及針對其他國家的計劃（傀儡日本征服蘇聯等等）...也都是在1942年1月1日後才可施行.

這其中有什麼原因嗎？或者說為什麼一定要從1942年起？為何不是在這之前或之後？
所謂的1942年美國有條件介入是指什麼歷史事件？事件的起因？主要人物？

In September, however, and once again early in November, Hitler appeared to waver another time and to prefer the idea of alliance. 「Führer hopes to be able to incorporate Russia into the front against England,」 Halder noted on November 1. But another entry only three days later pointed to the opposite: Hitler had said that Russia was going to remain 「the whole problem of Europe. Everything must be done in order to prepare for the great reckoning.」 These vacillations appear to have come to a stop in the course of December, when Hitler seems to havemade the decision that so thoroughly accorded with his nature, with his lifelong design, and with his present overestimation of himself: to begin the war with the Soviet Union as soon as possible. The re-election of Franklin Delano Roosevelt as President of the United States, and his conversation with Molotov, had evidently speeded the decision. At any rate, only a day after the Soviet Foreign Minister』s departure he commented that this would 「not even remain a marriage of convenience.」 He thereupon issued the order to scout out suitable terrain for a Führer』s headquarters in the East and for three command posts in the North, the Center and the South, and to build these 「with maximum haste.」

然後這是你說的這段

【On December 17 he expatiated to General Jodl on his operational ideas for the campaign, and concluded with the remark that 「we must solve all Continental European problems in 1941, since from 1942 on the United States would be in a position to intervene.」】

The decision to attack the Soviet Union even before the war in the West was decided has often been viewed as one of Hitler』s 「blind,」「puzzling,」 or 「hardly comprehensible」 resolves. Yet it contained more rationality, and at the same time more desperation, than is evident at first glance. Hitler himself ranked this order to attack as one of the many 「most difficult decisions」 he had to make. In the reflections that he dictated early in 1945 to Martin Bormann in the bunker beneath the chancellery, he declared: During the war I had no more difficult decision to make than the attack upon Russia. I had always said that we must avoid a two-front war at all costs, and moreover no one will doubt that I more than anyone else had reflected upon Napoleon』s Russian experience. Then why this war against Russia, and why at the time I chose?

................................

Why 1941?... Because we could allow ourselves as little delay as possible, since our enemies in the West were steadily increasing their fighting power. Moreover, Stalin himself was by no means remaining inactive. Consequently, time was working against us on both fronts. The question therefore is not: 「Why as early as June 22, 1941?」 but 「Why not earlier?」... In the course of the last weeks I was obsessed with the fear that Stalin might forestall me.

首先你要知道，希特勒對布爾什維克和蘇聯是恨之入骨的，他恨不得在1928年就把蘇聯滅了

具體上，有一件大事呢，作者好像沒提

就是1940年11月莫洛托夫訪德，提出蘇聯對芬蘭、波蘭、羅馬尼亞、達達尼爾的勢力要求

而莫洛托夫為什麼要訪德呢？那就是里賓特洛甫提倡的「四國條約」

簡單說，日本在往南打東南亞，德國也在往南打非洲，大家互不干涉，蘇聯你們也往南打吧

莫洛托夫是這麼表態的：

當天下午，莫洛托夫又在不動聲色地傾聽元首的陳詞。希特勒說完後，他客氣地抱怨說，元首的說法太一般化了，一點也不具體。他所需要的是細節。緊接著，他便提出了一系列令人難堪的問題：「1939年的德蘇協定是否仍適用於芬蘭？歐洲和亞洲的新秩序是什麼樣子？蘇聯在其中有什麼作用可起？保加利亞，羅馬尼亞和土耳其的地位又如何？在保護蘇聯在巴爾幹半島，和黑海的利益方面，現在的情況如何？」

當然，莫洛托夫特別小氣，鼠目寸光，一直就盯著芬蘭問題不放

希特勒：在波羅的海發生的任何衝突，都將使蘇德關係緊張——後果不堪設想。

莫洛托夫：這不是波羅的海問題，而是芬蘭問題

希特勒的表態就差一層窗戶紙了，而莫洛托夫死盯著芬蘭，認為希特勒是轉移話題

後來，英國飛機空襲柏林，里賓特洛甫和莫洛托夫進了防空洞

莫洛托夫就得理不饒人了，他乾脆跟里賓特洛甫說：你丫不是說英國快玩完了么？

這次訪問，不歡而散

另一方面，羅斯福一向是反對德國的，也一直主導對英國的援助

所以說羅斯福連任總統，這就是對希特勒最大的刺激，你要知道在1940年12月29日，羅斯福就在爐邊談話中提出了【民主國家兵工廠】的態度

至於作者提到的莫洛托夫和羅斯福的對話，相關細節不太清楚

無論如何，蘇聯拒絕和德國合作，那就只有對立，這樣美國自然會成為蘇聯的盟友

回到一開始，希特勒對布爾什維克和蘇聯是恨之入骨的

之後，希特勒說：

作為歐洲的守衛者和保護者的第三帝國，決不會讓這些友邦白白犧牲在共產主義的祭壇上。這種行徑是無恥的；若這樣做，我們必將遭到懲罰。無論在道義上還是在戰略上，這都是一著臭棋。不管做了什麼，與俄國交戰勢在必行。拖延開戰的時間，便意味著在不利得多的條件下作戰。因此，我決定，莫洛托夫一走，我便開始向俄國算帳——只要天氣許可。