It is this immanent gap that eludes Althusser's theory of the Ideological State Apparatuses (ISAs). According to Althusser, what distinguishes the State from other social apparatuses is that- Slavoj Zizek, "Absolute Recoil"...everything that operates in it and in its name, whether the political apparatus or the ideological apparatuses, is silently buttressed by the existence and presence of public, armed physical force. That it is not fully visible or actively employed, that it very often intervenes only intermittently, or remains hidden and invisible - all this is simply one further form of its existence and action... one had to make a show of one's force so as not to have to make use of it;...it suffices to deploy one's (military) force to achieve, by intimidation, results that would normally have been achieved by sending it into action. We may go further, and say that one can also not make a show of one's force so as not to have to make use of it. When threats of brite force, or the force of law, subject the actors in a given situation to obvious pressure, there is no longer any need to make a show of this force; there may be more to be gained from hiding it. The army tanks that were stationed under the trees of Rambouillet Forest in May 1968 are an example. They played, by virtue of their absence, a decisive role in quelling the 1968 riots in Paris.The first thing to note here is the radical change of terrain that occurs when we pass from the first to the second level of avoiding the use of direct force. First one makes a show of force so as not to have to use it; then, one does not make a show of force so as not to have to use it. We are effectively dealing here with a kind of negation of negation: first we "negate" the direct use of force by replacing it with a mere show - say, in a tense situation in which the authorities expect violent demonstrations, they decide to parade columns of tanks through the working-class quarters of the city, expecting that this will dissuade the protestors; then this "negation" is itself "negated", ie, there is no show of force, but the authorities expect this to have an even more powerful deterrent effect than an open display of force - since the protestors know there is a police (or military) force ready to confront them, its very absence makes it all the more ominous and omnipotent. The first negation operates at the level of the imaginary: the real of the brutal use of force is substituted by a fascinating spectacle designed to deter protestors. The second negation operates at the level of the symbolic: it is only within the symbolic order of differentiality that "the presence-absence (a presence rendered effective by its very absence)" functions, ie, that absence can count as a positive feature even more powerful than presence. And it is this properly symbolic dimension that Althusser ignores, as it is clear from a footnote attached to the quoted passage, in which Althusser draws attention to how Perry Anderson likened "the presence-absence... of the state's armed forces to the monetary gold reserves of the Central bank's:general circulation in all its forms (which are practically infinite) takes place independently of the presence of the gold stocks on the market. Yet, such circulation would be impossible if these reserves did not exist... they "impinge" on the market" simply because they make this market (this market and no other) possible, in exactly the same way as the invisible (should I say "repressed"? - that is indeed the right term as far as most people are concerned, since they "do not care to know" that these reserves exist and play a determinant role) presence of the police or armed forces impinges on a situation.From this second example, we can clearly see what Althusser misses: the "little piece of the real" (the armed force, gold reserves) that can remain in the background since it can perform its function without being used, that people believe there is an armed force hidden in the background (or gold reserves in an inaccessible bank vault). The real in the background that serves as the ultimate guarantee and support of the public power is thus a spectral entity- not only does it not need to exist in reality, if it did appear and directly intervene in reality, then it would risk losing its power, since as Lacan made clear, omnipotence (toute-puissance) necessarily reverts into "all-in-potency" (tout en puissance): a father who is perceived as "omnipotent" can only sustain this position if his power remains forever a "potential," a threat which is never actualized. The full use of force, painful as it might be, makes it part of reality and as such by definition limited. This- and not only the shame of what they had done - was the reason the Chinese authorities turned their crackdown at Tiananmen Square, in which (at least) hundreds died, into a non-event: it was a direct exercise of brute force, but it took place at night, invisibly, like a nightmarish-spectral event of rumor; peace and order were immediately restored, all traces of the conflict erased, the appearance of life carrying on as normal resumed. If a regime gets involved in open warfare against its own population, it risks losing not only the minimum of its legitimacy but the very source of its power.