Is there any relationship between tekhelet and shalom and achdut with klal yisroel?
The Radzyner Rebbi concludes his book “Ptil Tekhelet” with the following idea: And now God should bless Israel, in the merit of the mitzvah of tzitzit as it says, And He will remove from [Israel] all evil and all sickness and all wounds and all curses and all baseless hatred (sinat hinam), and as the RM”A from Pano explained (in Maamar Tzvaot Part 2): And know that Tekhelet has the gematria “Sinat Hinam”, and therefore it is possible to say that the reason why Korah dissented about tekhelet, because he had sinat hinam for Moshe and Aharon, and thus he mocked (mitlotzetz) the benefit (maalat) of tekhelet which ATONES (mechaperet) for sinat hinam, as I mentioned before why it atones for sinat hinam, but that is only when the person does teshuva gemurah and removes it from his heart. And it will benefit him greatly to reach this desire [apparently the tekhelet will help to facilitate the person to do teshuva over sinat hinam – M. Navon] – so ends the RM”A of Pano. And indeed this is the main thing which delays the redemption, as it says in Yoma (9b): but the second mikdash where the people were involved in Torah and Mitzvot and Gemilut Hasadim, so hy was it destroyed? Because of sinat hinam, which teaches you that sinat hinam weighs equivalent to the three sins of idol worship, illicit relations, and murder. And may God gather in our dispersed from the four corners of the earth, and redeem us soon and unify our hearts to love and fear His name to unify Him with love, and bless his people Israel with good life and peace. Also: – The Yeshot Malko wrote that the renewal of tekhelet is a sign of the geulah, and the geulah is of course to bring shalom. – Shoheir Tov on Tehilim 90 writes “If Israel wears tzitzit and tekhelet they would not be “achurin” (besmirched) because when they look at their tzitzit it is as if the shechina is present amongst them (shruya beineihem), and it is as if they are busy doing all the mitzvot.” And of course the shechina is not shruya unless there is achdut. – Mois Navon.