Consistency and principles are for when you're dealing with people who aren't disingenuous bad faith arguing opportunists who openly state they want to murder you and your loved ones.
Consistency and principles are always nothing more than a hindrance in adversarial scenarios. Your opponents will point out where you have not lived up to some principle or have been inconsistent, but this is not because anyone values these things or will respect you for upholding them; it is because they want to be able to read you like a book and plan around your consistent, principled, and entirely telegraphed moves. They would rather face an unintelligent and unchanging puzzle to be solved than an intelligent agent. If you and an opponent both agree to be principled, and you pick your principles first, your opponent may then pick a principled stance which defeats yours and happily stick to it.
If, instead of as a static defense for your opponents to pick apart, you wish to act with agency, you will not claim principles; if it were possible to fully understand and articulate your own goals as some principle, you could use that, but it never is. You hold your goals in mind, try to predict your opponent's moves based on their own goals and resources, and you fight for what you want. If one of your goals is that a political process is respected and has certain parameters, you can restrain your actions in order to encourage that while pursuing your other goals. If not, you do whatever you can with what you have.
Ultimately it all comes down to material gain and aesthetics. You have needs, wants, preferences, and some vision for the future. Your opponent has all of those as well, conflicting to some degree with your own, necessitating conflict. When you both want to live in a similar enough society, this can overrule petty competition for resources; when you want to live in different enough societies, unless you can separate and tolerate one another, to starve and destroy your opponent becomes a necessity.
