In the Sicha of Matos-Massei 5751, the Rebbe makes the following statement about Ahavas Yisroel:
The connection between Ahavas Yisroel and the future Redemption can be emphasized yet again, not only because the negation of exile comes through the negation of the cause of exile (which comes through the opposite of Ahavas Yisroel)… The emphasis on Ahavas Yisroel anticipates the beginning of the true and complete Redemption, which is connected with the point of unity above any division.
In other words, there are two reasons for having Ahavas Yisroel: Firstly, to rectify the problem that caused the exile, and second, to begin adjusting to the life of the future - the life of Moshiach - where there will be no war, jealousy and hatred. The Rebbe wants us to have Ahavas Yisroel primarily for the second reason.
What is the practical difference between the two motives to have Ahavas Yisroel?
If the impetus to have ahavas Yisroel is fixing the reason for Galus, then in reality it is not true Ahavas Yisroel. You have a problem (galus) and the panacea to your problem is Ahavas Yisroel, so in essence it is all about you. That kind of Ahavas Yisroel is selfish; it’s not really because you love the other. The second way of Ahavas Yisroel however - when one is living Geula and sees the Yechida in every Yid - the love is unconditional; it is all about the fact that the other person has a Neshama.
The difference is also felt by the other person. There is a famous story about a bachur who went on Mivtzaim and asked someone to put on T’fillin and the person refused. R’ Mendel Futerfas then asked the same person to put on T’fillin and the person agreed. The first bachur asked the person why he agreed to put on T’fillin with R’ Mendel but not with him.
The man replied, “When you asked me, I didn’t feel that you really cared if I put on T’fillin, rather I felt that you were trying to get the biggest number of people to put on T’fillin. When R’ Mendel asked me to put on T’fillin, I felt that he really cared that I should put in T’fillin, so I agreed.”
This echoes a very similar statement that the Rebbe made a few weeks earlier (Balak 5751 in middle of ois 9) in regard to learning about the Beis HaMikdash in the three weeks: “The learning should not just be because you feel the feelings of mourning of the destruction, and therefore the need to fix the void of, the second Beis HaMikdash. Rather - (even if the Beis HaMikdash was never destroyed) because you are anticipating the greatness of the third Beis HaMikdash!”
We need to be forward thinking and that comes through living with the future in our actions. In the words of the Rebbe: “We should ‘live with the time’ of the Messianic Era. This can be attained when one’s intellect is filled with the comprehension of the Torah concepts of Moshiach and Redemption. This intellectual awareness then extends to and permeates one’s emotions, and then translates into thought, speech and action consistent with this very auspicious period of time when we stand on the threshold of Redemption and we are able to point with our finger ‘Behold he (he King Moshiach) has come.’”
This theme is also expressed in the special Chabad custom during the nine days (and in 5751, the Rebbe encouraged it to continue till 15 Av!) to make a daily Siyum. While many communities hear Siyumim in the nine days, they do it to enable them to eat meat. The Chabad custom is to hear Siyumim and refrain from eating meat at the same time.
The Rebbe did not want Torah (siyumim) to be a “problem solver” for our physical desires of eating meat in the summer, but rather, because we want to connect and rejoice with Hashem through his Torah. Being that we want to make a “siyum” end of Galus, and we want to show Hashem that we are anticipating the “Torah Chadasha” of Moshiach, we continue the Siyumim through 15 Av!