During WW2:

There was already a route to USA and Palestine through Russia during WW2.

Add-in:

20 articles mostly from the Jewish Telegraphic Agency, between 1939-1945, reporting the Soviets evacuating up to 1.8 million Jews deep into the Soviet Union, saving them from the Nazis:

The immediate aftermath of WW2:

General Morgan in the official report of the British Government on Expenditure in Austria (1946):

“Very large numbers of Jews, almost amounting to a second Exodus, have been migrating from Eastern Europe to the American zones in Germany and Austria, with the intention in the majority of cases, of finally making their way to Palestine. It is clear that it is a highly organised movement, with ample funds and great influence behind it, but the Sub-Committee were unable to obtain any evidence who are the real instigators.”

In Morgan's 1961 autobiography Peace and War, a Soldier's Life, he details how the UNRRA was a Zionist tool, how Jews from Eastern Europe were smuggled into post-war Germany to 'Jews Only' displaced person camps and were then evacuated to Palestine.

Here is some coverage of Morgan’s accusation that the Jews were carrying out a carefully planned exodus of Europe in the immediate aftermath of WW2.

General Morgan who made public and detailed the fact that vast numbers of Jews were arriving in Occupied Germany from Russia, and that he knew elements within the American and Soviet governments were working with Zionists in a planned Jewish exodus of Europe, was defended in Parliament by Sir Peter MacDonald:

“We heard that in the British zone in Austria there were U.N.R.R.A. camps occupied by Jews […] we found 5,000 or 6,000 Jews, who were there because the general commanding the American zone had asked our Commander-in-Chief if he would take these people off his hands temporarily, because his own zone was overcrowded with the same type of displaced person. […]
When Russia occupied Eastern Poland some of them were sent to Russia to work, and they worked there during the war. […] We had to state in our report that we could not trace the origin of this organisation, but the organisation is there, and there is no doubt whatever that the Russian Government are conniving at it. These people were brought down from Poland into Czechoslovakia, where they were fitted out with passports, clothes and money, and transported into the American zones in Germany and Austria. From there, they hoped to find their way to Palestine.
This type of emigration to Palestine is not, I hope, one which the Government are being asked to encourage, because these are recruits for the Jewish Army, and that is why they are on their way to Palestine, with the connivance of the American and Russian Governments. […]
Because of General Morgan's great skill as an organiser, he was selected for this job of British representative on U.N.R.R.A. He was deputy to the heads of U.N.R.R.A—first Mr. Lehman and later ex-Mayor La Guardia —and because he told the truth in regard to the exodus of Jews, through Europe, to Palestine, he was suspended. Later he was reinstated for a time and then he was dismissed from his post by ex-Mayor La Guardia, and a Mr. Cohen was appointed in his place. Now we are told that he has been dismissed from the Army and given a bowler hat—not at his own request—at the age of 53. I think that is, a scandal. We can ill afford to lose the services of men like General Morgan when the Army is being reorganised as it is today. I consider that that soldier has had a very raw deal, just because, on this occasion, he exposed this exodus of Jews through Europe.”

Hence:

The Jews carried out a carefully planned exodus of Europe in the immediate aftermath of WW2

Hitler’s ascension to power was needed as the last step toward Zionist goals. Without this uprooting process initiated by him, the modern Zionist state would not be a reality today.

The Canadian Jewish Chronicle - Aug 9, 1935:

“What the Nazis want and are aiming at is really not emigration, but an exodus of the Jews.”

Ben-Gurion's memoranda: Outlines of Zionist Policy, March 7, 1941:

“The establishment of Jewish State has now become an indispensable means of achieving Zionism under the NEW POST-WAR CONDITIONS (Uprooted Jews thanks to Hitler) [...] It must be clearly realized - and it is the task of Zionism to make the world realize (at least, the Anglo-Saxon world) - that immediately after the end of the war it will be faced with a mass exodus of Jews from Europe, and that these Jews, whatever the regime in Palestine, will surge IRRESISTIBLY towards that country: Palestine will have to absorb the largest number of Jews in the shortest possible time.”

“A clandestine, Zionist-organized mass movement of about 250,000 Jews from Eastern and Central Europe following the Holocaust” (source)

Josh’s research archive

Routes from Russia to Palestine & USA during…