The rectification of the political state as a whole
Tikkun is a Kabbalistic term that means the rectification of the world - bringing it into conformity with the purpose of creation.
The government is the national body, and in this sense, the act of rectifying it is parallel to the individual's rectification of his physical nature.
The rectification of the material body (and, in particular, of the government as the material body of the people) holds such a high potential for holiness that this holiness must be concealed, as such a revelation would cause the world to drown in it, destroying the existing order of the universe.
This refers to those situations in which the structures of government (or the material body of the individual) are affected in the fulfillment of clear, concrete commandments.
Tallit: The four-cornered prayer shawl to which tzitzit are attached
The tallit is "simply a garment"; but people need garments for warmth, for proper appearance, and to construct civilization, through which humankind's divine potential is revealed. The holiness of the tallit is not obvious, whereas that of the tzitzit attached to it is open and visible. But it is only the existence of the tallit that makes possible the fulfillment of the commandment to wear the tzitzit. Yet the tallit is also a reservoir of immense hidden holiness, only some of which is revealed through the tzitzit.
Note that the word tzitzit is derived etymologically from a root meaning to "show on the outside." Thus the concealed holiness of the tallit shows through the tzitzit.
In other words, God's purpose for Creation is the realization of holiness in the material world; therefore, everything material - every person and entity - contains great potential holiness. We see a small obvious manifestation of this holiness (the tzitzit in relation to the tallit) when the material - including the body, society, the state, civilization - gives us the opportunity to carry out specific commandments. Ultimately, however, it is not these commandments in and of themselves, but of the gradual revelation of that hidden potential holiness contained in the body itself (society, state, civilization). Then, even matters of ordinary, transient life will "make visible the light of eternal life." Therefore, the rectification (tikkun) of the material (including the body, state, and civilization) encompasses immense although not obvious, holiness.