|It doesn't stop at the water's edge:|
“”Power is not a means; it is an end. One does not establish a dictatorship in order to safeguard a revolution; one makes the revolution in order to establish the dictatorship. The object of persecution is persecution. The object of torture is torture. The object of power is power.
|—George Orwell, 1984|
Authoritarianism is a very interesting phenomenon. Its adherents don't necessarily want to "tell you what to do" - as long as, if they disagree with you, someone else in power will tell you what to do.
It is this honoring of power over reason that makes an authoritarian. The authoritarian loves rules, and loves to apply them. However, for a true authoritarian, power is more important than rules: the rules themselves aren't the source of power and they don't apply to the powerful. Oceania had no laws - it didn't need them. Crime was simply whatever the authorities said it was.
Usually the first step in any would-be authoritarian is to arrange blanket exemptions to civil and constitutional protections for broad groups of people (people accused of certain crimes, for example), and give power to the armed forces or the police to act outside of the law.
On a site such as this, which is run as a mobocracy - that is, pretty much an anarcho-syndicalist arrangement — authoritarians find themselves lost, as we care more about the spirit of our "rules" than strict adherence to them.
People who are raised to strictly follow specific writings as unquestionable display a strong tendency towards authoritarianism. As such they are very dangerous to democracy and the health of any society in which they live.
 In government
Authoritarian governments seek to perpetuate the power of the rulers. They will often use the fear of disorder to justify their rule, as in Egypt, which was under a continuous state of emergency that started in 1981 and ended in 2011 when Hosni Mubarak was finally deposed from power. Full state control over the media is also a common component of authoritarian control, as it allows the government to effectively control the populace's views, particularly of foreign events. Religious policies vary, ranging from theocracy to complete suppression; the common thread is the suppression of the potential threat posed by independent religious leaders. Heavy-handed policing and arbitrary detention suppress any dissent that survives the government's other methods of control by placing the regime's opponents in government custody.
Some, like Jeane Kirkpatrick, have tried to make a distinction between "authoritarian" and "totalitarian" regimes. The general idea is that authoritarian regimes still allowed for some (mostly economic) freedom, and thus could be reformed, unlike the completely dominating totalitarian ones. Most see this as a desperate attempt to make it OK for Ronald Reagan to have supported authoritarian regimes, while he still blasted the Soviet Union on its human rights problems.
Research shows that authoritarians are far more likely to exhibit "sloppy reasoning, highly compartmentalized beliefs, double standards, hypocrisy, self-blindness, a profound ethnocentrism, and -- to top it all off -- a ferocious dogmatism that makes it unlikely anyone could ever change their minds with evidence or logic."
Authoritarianism can also exist in a nominally left-wing situation -- cults of personality such as Stalin's or the Kim family's are examples. Other such examples might include the French Reign of Terror, in which egalitarianism was twisted into a chaotic witch hunt that consumed its own leaders (including Maximilien Robespierre himself), left-wing purity trolls (including the centrist PUMA movement in American politics), and the Judean People's Front.
Although many libertarians and anarchists have attempted to equate the two, statism and authoritarianism are not the same thing; although most authoritarians are statists, so are quite a lot of people who believe one of the functions of government is to enforce civil rights.