It is. The word Islam and Salaam are etymologically tied to the word "peace".
If your definition of peace is "never wages war", well there's no country or political regime in the world like that. Even India, which was liberated by the famous nonviolent philosopher Gandhi, did not last many years without needing to wage war and take territory.
Islam is the only remaining religion with a political element and an existing desire for statehood. You could argue for Judaism (but some of the Orthodox would disagree) also. Back when Christendom had aspirations of statehood, it was also not "peaceful" in the way most people imagine. But this isn't a feature of the religions. It's a feature of world politics. No one can be peaceful and engage meaningfully in world politics. Everyone is propped up by some army somewhere.
You can have many arguments against the social regime, views on gender, etc. Etc. of Islam, but to say it's not peaceful because it is a political entity is just not understanding politics or the world, imo