One common approach to arguing in favor of civilian gun rights is to claim that such rights prevent, deter or at least provide a defense against tyranny. In general, the idea seems to be that the people in power will be less inclined and less able to impose tyranny if the civilian population possesses the right to keep and bear arms. In the United States, this is presented in terms of the members of the government deciding to impose tyrannical rule over the people.
On the face of it, this justification does have some appeal. After all, if the government has to overcome armed civilians, then it would obviously be harder than using force against unarmed civilians. Also it could be argued that politicians might fear that they would be assassinated by armed patriots if they started acting in tyrannical ways.
People also point to the American Revolution and claim that the fact that the civilian population was armed was an important factor in the American victory over the British tyranny. Those with some science-fiction leanings also present counter-factual scenarios in which one is asked to imagine what would have happened in Germany if the Jews and anti-Nazi Germans had possessed the right to keep and bear arms (or were at least armed). Stalin and other dictators are also often brought up in this context. The idea is, of course, to appeal to the intuitions of the audience and persuade them that if only the Germans had had their own Second Amendment, then Hitler might have never been able to come to power and the Holocaust might not have happened.
The idea that the cowardly politicians who dream of tyranny are kept in check by red-blooded Americans exercising their constitutional right to keep and bear arms does have a certain emotional appeal. So too does the thought of armed plucky rebels defending America from tyranny. In fact, such scenarios would no doubt make for successful Hollywood films. But what is appealing and what might make a blockbuster film are not the same as what is, in fact, true.
Naturally enough, the general idea of the role of civilian armaments in deterring tyrants can be debated extensively. This is, of course, a worthwhile debate and would be a rather interesting project for historians to sort out. However, what is under discussion here is the rather specific matter of whether or not the right to keep and bear arms is warranted by the deterrent value of this right against tyranny. This, obviously enough, involves some key matters of fact.
One obvious matter of fact is the issue of whether or not gun rights frightens politicians with tyrannical intentions—that is, whether worries about assassination keep them in check.
As argued above, it makes sense to think that a politician would be less inclined to do something if she believed doing so would result in people attempting to kill her. Naturally, if the population has easy access to firearms, then an assassin could easily acquire a gun. If there were strict controls on guns, then politicians would have less to worry about in terms of assassins drawn from the ranks of the general population. They would just have to worry about the military and police forces (and anyone who could make a bomb or wield a knife). Obviously, even in a state with strict civilian gun control, the politicians would need to win over the majority of the military and police forces to their tyrannical agenda—or their attempts at tyranny would end rather quickly. In the United States, this would require winning over the national forces (the military, FBI, and so on) as well as the state (National Guard and state police) and local forces (police and sheriffs).
Interestingly, democratic states with stricter gun control than the United States, such as the United Kingdom, do not seem to have fallen into tyranny. This suggests that it is not fear of assassination by citizens exercising their guns rights that keeps a democratic state from tyranny, but rather other factors. But perhaps they are just biding their time and the United Kingdom will soon be back under an absolute monarchy.
A second obvious matter of fact is the issue of whether or not civilian gun ownership would deter the military and police forces from imposing tyranny on the people at the behest of the tyrant(s). This, of course, assumes that the tyrant(s) has won over the majority of the military and police forces to her plot of tyranny and that there is no significant opposition from the military and police forces that are not in on the tyrannical take over. That is, the tyrant has won over the American citizens in the military and police forces to the degree that they would be willing to throw aside the Constitution and turn their weapons against the general population—including their friends, family, spouses, and children.
In such a scenario, it would seem that civilian weapons would be of little use. After all, the military and police forces of the tyrant would have military weapons (tanks, attack helicopters, bombers, artillery, ships, nukes and so on). Handguns, rifles and shotguns would be of rather limited use against such forces. Back in the time when civilian weapons and military weapons were essentially on par (muskets) and the most destructive military weapons were very limited (muzzle loading cannons) an armed civilian population would reasonably be regarded as a deterrent. However, it is hard to imagine suburban Americans battling successfully against tanks, Predator drones, and Hellfire missiles using AR-15s and .38 specials. That said, there is something to be said for an honorable death fighting against impossible odds.
Of course, the civilians could turn to the sort of tactics used by insurgents and terrorists to resist the military and police of the tyrant—but this would not be a case of the right to keep and bear arms deterring tyranny. However, the main thing that seems to defeat tyrants is a lack of support-without that a tyrant is a just a single man.
Naturally, it can be pointed out that civilian arms could be used to resist a small scale tyrannical incursion (perhaps a takeover in a small town). However, in such a scenario the tyrant would soon be dealt with by the police or military of the state. Also, the main deterrents against American tyrants grabbing American towns would seem to involve not guns but other factors—like an unwillingness to go along with a tyrant.
It would thus seem that civilian gun ownership would be little, if any, deterrence or defenses against a serious tyrant. It is also interesting to note that if such armaments provided considerable power against the state, there would be the fear that they would be used by a segment of the population to impose their own tyrant on others.
In light of the above, the defense against tyranny argument would seem to provide little in the way of justification for civilian gun rights. This should not be terribly shocking—after all, the second amendment does not justify the right to keep and bear arms in terms of having an armed population ready to shoot it out with other armed citizens.
There are, however, good reasons for gun rights, but these are beyond the intended scope of this essay.