Divine Accusation against those that don't help the ingathering of the exiles

[edu]

For the sake of ease I will make use of an existing translation of Kol Hator, which describes the Vilna Gaon's views about the Redemption as recorded by his disciple
http://www.yedidnefesh.com/kaballah/kol-hator/1.htm
 

[e].  escapees [refugees] in Zion.  The fifth principle is that [Joel 3:5] “for in Mount Zion and in Jerusalem there will be those who escape, ...  and among the remnant, those whom the Lord will call.” Since according to Midrash Tanchuma, Zion is in the line of Mashiach Ben Yosef, whatever befell Yosef, befell Zion.  The Gaon said that this is hinted at also in the word “among the remnant” which in gematria equals  “Mashiach ben Joseph” [566], by means of whom, according to the Gaon, the ingathering of the exiles will be accomplished.  As the number of ingathered increases, so the Sitra Achra will increase its strength.  Then another prosecutor will be added, against those who do not strengthen the ingathering of exiles after the beginning of the Redemption has started with the ingathering, for then in “Zion and in Jerusalem there will be those who escape, ...  and among the remnant ...  .” A word to the wise is sufficient.  This worried the Gaon a great deal.

In chapter 34, of Ohr Haraayon, Rabbi Meir Kahane uses this as one of his sources to explain the Holocaust.
To put it bluntly, in my own words, when there is insufficient support of the Jews towards, the practical aspects of Zionism, that is to say the natural actions towards bringing about the ingathering of the exiles, don't think that Hashem is tolerant about this. Rather he raises political, economic, religious and/or social forces in the world to make it uncomfortable for those anti-zionists in the world to continue life as usual.