I will dwell in the midst of the children of Israel and I will be their God. (Exodus 29:45)

The Gaon of Vilna quotes the Mishna [Avot 1:2] which states:
Shimon the Righteous was one of the last of the men of the great assembly. He used to say: "The world stands upon three things: the Torah, the Temple service, and the practice of acts of kindness (g'milut ḥassadim)."
The Gaon comments that since Israel has been exiled from its Land and distanced from its soil, we no longer have Torah nor service. Torah is missing, as the verse in Lamentations [2:9] states: "her king and princes are (exiled) among the heathens, (and) there is no more Torah," and the Sages expounded "Since the Jewish people were exiled from their place, there is no greater dereliction of the study of Torah than this." [Babylonian Talmud, Ḥagiga 5b] Service, which of course took place in the Temple, is lacking as the result of the Temple's destruction.
Based upon this, the Gaon explains that following the amida, we pray:
May it be Your will that the Temple be rebuilt speedily in our days and grant us our portion in Your Torah.
The first request is to rebuild the Temple in order to be able to resume the service, the second is to be able to renew our connection to Torah. That is, we pray for God to rebuild the two missing (or at least significantly weakened) pillars upon which the world stands.
In essence, the sole pillar of the world which remains intact is g'milut ḥassadim. The Gaon quotes our Sages' comment that when the Temple was destroyed, our ancestors cried and wondered if there will ever be a revival, since we have lost Torah and service. Rabbi Yoḥanan ben Zakai responded: "We have one thing left, namely g'milut ḥassadim, as Scripture states "The world will be built of kindness (ḥessed)." [Psalms 89:3]
As a result of the destruction of the Temple and Israel's exile from the Holy Land, two of the three pillars upon which the world stands have been destroyed (or at the very least significantly damaged). Perhaps this is the reason we live in an upside-down world. The rectification will come with the return of all Israel to our Land and the rebuilding of the Temple, speedily in our days, Amen. (David Magence)

Shabbat Shalom!
The Va’ad