For the sake of completeness the following ruminations are the result of a story arc in the Day By Day cartoon by Chris Muir, beginning here, which resulted in a comment by me here. Some of the responses to my comment led me to consider some questions which in turn led to the following ruminations. I in no way mean to imply any endorsement of the following by Mr. Muir or anyone else. The reader is encouraged to read the DBD cartoon for the required context and background.

I will start with the question of whether or not Zed's views on sucker punches have a bearing on whether he was in the right.

My initial inclination was that so long as Zed was comfortable with being sucker punched, then his use of the same was acceptable. There are two problems with this however. First it suggests that there are two sets of rules, one for him and one for other people. Second is then the question of how are others to know which set of rules apply to him. History is replete with examples if what happens when different people in a society live by different rules, e.g. the aristocracy prior to the French revolution, the oligarchs in Soviet Russia, or the Jews in pre-WW2 Germany (who  were required to wear arm bands to identify which set of rules applied to them) to name a few. If we take the lessons of history to heart we quickly conclude that multiple sets of rules, whether identified or not, never results in a good outcome.

This then brings us to the the other question raised. Specifically whether we are bound by a social contract if only part of that contract is enforced.

To examine this question we must understand the purpose and structure or a social contract. A social contract defines at set of shared rules which allow individuals who may be unknown to one another to interact with a minimum of conflict. These rules take the form of combined obligations and privileges, i.e. provided that you behave in a certain way you can expect certain privileges in return. If the obligation half of the contract is discarded then the structure fails to perform its primary function and there is no social contract. Conflict will inevitably increase and the society will eventually collapse from within. Thus the purpose of a social contract is to allow a group of people to function with minimum conflict.

This is where a mental leap occurs.

Upon consideration of the above we see that, at least in part, the current difficulties between the Western world and the Muslim population arise due to conflicting social contracts. This can be most clearly seen in recent events in Europe regarding Muslim refugee attacks on women and children, e.g. here and here. The refugees are acting in accordance with the social contract with which they are familiar. Note that I am intentionally setting aside any consideration of the relative merits of the conflicting social contracts.

This in turn leads to the consideration of the fundamental flaw in multiculturalism.

Different cultures and their attendant histories result in different social contracts. Assimilation is at its core the process of learning the social contract of a new culture. Failure to assimilate can only result in conflict as no social contract is shared. Thus the insistence of multiculturalism on eliminating assimilation cannot work. Further we can see that any attempt to enforce a social contract on another culture is doomed to failure, the requisite history and cultural institutions are missing. This is why so called nation building, and its more generically labeled kin "spreading democracy/capitalism", has always failed. For an excellent commentary on a recent example of such a failure I recommend the series of articles by Jayant Bhandari on recent events in India.

The only way to successfully alter a social contract is for the related culture to choose the change or by the complete destruction of said social contract. In the later case history teaches that the outcome will rarely be as hoped for.

After that rather cerebral detour; to answer the original questions, noting that we can only answer them in a theoretical fashion.

First, Zed's views on sucker punches are not if fact germane. To the extent that his purpose was to preempt future conflict with Sam (which we can assume from dialog at the end of the arc) he was in the wrong as it violates the wider social contract in place in the US. Nor is his training as a sniper any defense as those skills are intended for application outside of his social group, hence in situations where the social contract does not apply.

Second, to the extent we expect others to abide by the previously shared social contract we are ourselves bound by it. Care must be exercised here as we are currently in a period of history where the social contract is in flux as a result of the obligation half having been discarded in modern history. Any attempt to enforce the pre-existing social contract will, in the long run, most likely fail as the underlying culture is changing. Until a new point of stability is reached in the culture no new social contract can be completely forged.