If a law is unjust, one may break it. But it is not the case that if one merely believes a law to be unjust, one may break it; it depends upon whether one’s belief is correct.
There are many cases in which we cannot tell whether a law is just or unjust; justice is a difficult subject . What ought we to do then? In cases where we do not know whether the law is just, we will simply not know whether it is permissible to break that law. I can say nothing here that will cause readers to be able to know in all cases what is just or what they ought to do. My only advice for such situations is that one do further research on the topic (perhaps in the ethical and political philosophy literature) and then exercise one’s best judgment.
To some, this view will be unsatisfying. A more satisfying view would be one that provides a simple, more or less mechanical rule for what to do in all cases. For instance, if we could say , ‘When in doubt, always obey the law’, many would find this a more satisfying position than the position that we sometimes cannot tell whether we should obey the law or not.
But satisfyingly simple and convenient rules are not therefore correct. In particular, there is no reason to think that whenever there is doubt as to the justice of a law, it is better to obey than to disobey that law. Suppose a soldier has been ordered by his government to fight in a war. The soldier is unsure whether this order is just, because he is unsure whether the war itself is just. Nothing in this description of the case enables us to infer that it would be right or good for the soldier to fight in the war. If he fights, he may be participating in mass murder. We do not know enough to say whether this is the case. The crucial information we would need, before we could advise the soldier as to what he ought to do, is a piece of moral information: we need to know whether the war is just. The fact that this knowledge may be difficult or even impossible to obtain does not prevent it from being the relevant and necessary knowledge for addressing the question at hand, nor does it enable some other, more easily knowable fact to settle the question. It simply is the human condition that our ethical questions frequently have no easy answers.
Huemer, Michael (2012-10-29). The Problem of Political Authority: An Examination of the Right to Coerce and the Duty to Obey (pp. 170-171). Palgrave Macmillan. Kindle Edition.
I think we can say that one ought not enforce laws or policies that one does not know to be just. The simple rule “When in doubt, do not coerce“ seems valid. Therefore if we lack crucial information necessary to determine whether a war is just then we should advise the soldier not to participate until the war is known to be just.
Consider Bryan Caplan’s common sense case for pacifism:
1. The immediate costs of war are clearly awful. Most wars lead to massive loss of life and wealth on at least one side. If you use a standard value of life of $5M, every 200,000 deaths is equivalent to a trillion dollars of damage.
2. The long-run benefits of war are highly uncertain. Some wars – most obviously the Napoleonic Wars and World War II – at least arguably deserve credit for decades of subsequent peace. But many other wars – like the French Revolution and World War I – just sowed the seeds for new and greater horrors. You could say, “Fine, let’s only fight wars with big long-run benefits.” In practice, however, it’s very difficult to predict a war’s long-run consequences. One of the great lessons of Tetlock’s Expert Political Judgment is that foreign policy experts are much more certain of their predictions than they have any right to be.
3. For a war to be morally justified, its long-run benefits have to be substantially larger than its short-run costs. I call this “the principle of mild deontology.” Almost everyone thinks it’s wrong to murder a random person and use his organs to save the lives of five other people. For a war to be morally justified, then, its (innocent lives saved/innocent lives lost) ratio would have to exceed 5:1. (I personally think that a much higher ratio is morally required, but I don’t need that assumption to make my case).
Thus war cannot be justified unless one knows with high confidence that the long-run benefits will substantially exceed the short-run costs. In practice this standard is rarely met.
Caplan’s standard applies to an individual soldier as well as it applies to a nation.by