Peace surely is a good reason, yes. But there are other reasons too.

Thus I assume that to each according to his threat advantage is not a conception of justice.

The intolerant can be viewed as free-riders, as persons who seek the advantages of just institutions while not doing their share to uphold them.

No one deserves his greater natural capacity nor merits a more favorable starting place in society.

I'm concerned about the survival, historically, of constitutional democracy.

Different political views, even if they're all liberal, in the sense of supporting liberal constitutional democracy, undoubtedly have some notion of the common good in the form of the means provided to assure that people can make use of their liberties, and the like.

First of all, principles should be general. That is, it must be possible to formulate them without use of what would be intuitively recognized as proper names, or rigged definite descriptions.