The potential for a Jew to bring about the refinement of the nations of the world,וְהִנֵּה בִּכְדֵי לִפְעוֹל הַבֵּרוּר דְּאֻמּוֹת הָעוֹלָם,
and, especially, those who are adversaries,וּבִפְרָט דְּאֵלּוּ שֶׁמְּנַגְּדִים,
comes about through arousing and revealing the dimension of yechidah within his soul.הוּא עַל יְדֵי הִתְעוֹרְרוּת וְגִלּוּי בְּחִינַת יְחִידָה שֶׁבַּנֶּפֶשׁ.
The yechidah constitutes the essence of the soul, which is intrinsically bound up with G‑d’s Essence. The revealed powers of the soul relate to the world from the perspective of a created being. Every entity possess its own individual identity and that is its focus. By contrast, the essence of the soul views all existence as G‑d views it: that it possesses no independent being and exists solely as an expression of G‑dliness. This conception encompasses not only the soul’s own existence, but extends even to those elements of the world – the non-Jewish nations who oppose the Jews – that appear most removed from G‑d. From the standpoint of the yechidah, everything exists solely to express G‑d’s being.
Since the sparks of G‑dliness embedded in these nations are utterly hidden and concealed,דְּכֵיוָן שֶׁהַנִּיצוֹצוֹת שֶׁבָּהֶם הֵם בְּתַכְלִית הַהֶעְלֵם וְהַהֶסְתֵּר,
Everything in the world, even those forces that are in total opposition to holiness, must contain some sparks of holiness in order to exist. However, these sparks are totally concealed, in no way manifesting their G‑dly nature.
therefore,1 the refinement of these utterly concealed sparks can only be achieved through a Jew arousing the very core of the soul, that G‑dly dimension that is ordinarily beyond expression and revelation:לָכֵן, בֵּרוּר נִיצוֹצוֹת אֵלֶּה הוּא עַל יְדֵי הִתְעוֹרְרוּת נְקֻדַּת הַנֶּפֶשׁ שֶׁלְּמַעְלָה מֵהִתְפַּשְּׁטוּת וְגִלּוּי,
the yechidah of his soul.יְחִידָה שֶׁבַּנֶּפֶשׁ.
In simple terms,וּבְפַשְׁטוּת,
by arousing his yechidah,דְּעַל יְדֵי שֶׁמְּעוֹרֵר בְּחִינַת הַיְּחִידָה שֶׁבּוֹ
a Jew is able to stand firm with resilient strength in the face of all challenges.הוּא עוֹמֵד בְּתוֹקֶף חָזָק,
For the unyielding strength that is needed to carry out his Divine serviceשֶׁבִּכְדֵי שֶׁיִּהְיֶ' לּוֹ תּוֹקֶף חָזָק לַעֲבוֹד עֲבוֹדָתוֹ
(without giving thought to his opponents)(מִבְּלִי לְהִתְחַשֵּׁב עִם הַמְּנַגְּדִים)
comes about through arousing his yechidah.2הוּא עַל יְדֵי הִתְעוֹרְרוּת הַיְּחִידָה שֶׁבּוֹ,
Ultimately, this unyielding inner strength will affect even those who oppose G‑dliness and transform them into abetting forces (as explained above in sec. 6).וְעַל יְדֵי תּוֹקֶף זֶה פּוֹעֵל סוֹף סוֹף גַּם עַל הַמְּנַגְּדִים שֶׁנֶּהְפָּכִים לִמְסַיְּעִים כו' (כַּנִּזְכָּר לְעֵיל סְעִיף ו).
This leads to a further concept: Even though this development (the transformation of adversaries into abetting forces)וְאַף שֶׁעִנְיָן זֶה (שֶׁהַמְּנַגְּדִים נֶהְפָּכִים לִמְסַיְּעִים כו')
is (seemingly) merely the result of the revelation of the yechidah he inherently possesses,הוּא תּוֹצָאָה (לִכְאוֹרָה) מִגִּלּוּי הַיְּחִידָה שֶׁבּוֹ,
this transformation nevertheless possesses an advantage over the revelation of the yechidah,מִכָּל מָקוֹם, יֵשׁ בָּזֶה עִלּוּי לְגַבֵּי הָעִנְיָן דְּגִלּוּי הַיְּחִידָה.
for nothing new is achieved through the revelation of the yechidah. On the contrary, it is an ever-present, latent power, lying at the core of every Jew’s being.כִּי בְגִלּוּי הַיְּחִידָה לֹא נַעֲשָׂה דָּבָר חָדָשׁ,
In contrast, the fact that an adversary transformed into one who abets (contrary to his natural tendency) is a novel development.מַה שֶּׁאֵין כֵּן זֶה שֶׁהַמְּנַגֵּד נֶהְפַּךְ לִמְסַיֵּעַ (הֵיפֶךְ הַטֶּבַע שֶׁלּוֹ) הוּא הִתְחַדְּשׁוּת,
As explained in Chassidus,3 the focus is on the transformation of those who by nature oppose G‑dliness. Since opposition to G‑dliness lies within their very nature, their transformation into positive influences is a novel development. It is not a measured step of refinement, but a drastic revolution resulting from breaking through their shell of spiritual insensitivity and uncovering the spark of G‑dliness innately present within them, which does not ordinarily come to the fore in their day-to-day existence.
A Jew’s ability to bring about such a transformation stems from the revelation of his own inner G‑dly core that transcends his individual identity. G‑d “alone has the power and the potential to create some­thing from nothing and absolute non-being.”4 And He “transferred,” as it were, this power to achieve something new to the Jewish people, enabling them to make a dwelling for Him in the lower realms.5 See also the explanations in sec. 10.
Moreover, it is specifically through such service that G‑d’s intent and desire for a dwelling in the lower realms will be consummatedנוֹסָף שֶׁעַל יְדֵי זֶה דַוְקָא נִשְׁלֶמֶת הַכַּוָּנָה דְּדִירָה בַּתַּחְתּוֹנִים,
in this material world, the lowest of all realms.בַּתַּחְתּוֹן שֶׁאֵין תַּחְתּוֹן לְמַטָּה מִמֶּנּוּ.

Summary

The potential to bring about the refinement of the nations of the world, and, in particular, those who are opponents, comes about through a Jew’s arousal of the yechidah within his soul. Since the sparks of G‑dliness embedded in these nations are utterly hidden and concealed, the refinement of these sparks is achieved by a Jew awakening the very core of his soul that is beyond expression and revelation. The revelation of the inner core of G‑dliness within a Jew, the yechidah, awakens the essential G‑dly core that exists even within these adversarial forces.
The revelation of the latent G‑dly sparks existing within these entities is an utterly novel development, which as such possesses an advantage over the revelation of the yechidah that already exists within a Jew’s soul.