In response to the current war in Israel, and the current situation (as I write this: hundreds of Israelis held hostage by terrorists, including children and the elderly), the organization Hadar has called for a ta'anit tzibbur (a communal fast). The announcement of this communal fast says:
Please join us this Thursday, October 12th, the 27th of Tishrei, for a communal fast day supported by rabbis and leaders from across the Jewish world. The fast will begin at dawn and end at nightfall.
I am curious about the phrase "supported by rabbis and leaders from across the Jewish world". Hadar is a progressive organization that promotes egalitarian interpretations of Jewish law, and for that reason alone I suspect many Orthodox rabbis would be reluctant to be associated with them, even on an issue that (arguably) ought to transcend such issues. On the other hand, few would argue against the basic premise, i.e.:
We have a traditional practice for moments like this one: ta'anit tzibbur–a fast that draws in the entire community to unite for deliverance for those in crisis.
So I am interested: have any Orthodox rabbis, or rabbinic organizations (e.g. the RCA, OU, CRC, etc.) joined in this call?
(This question is obviously time-sensitive, and therefore I am unsure whether it is within the scope of the site. Apologies if it is inappropriate. I'm also not sure what the appropriate tags are, so please feel free to edit.)