Would the USA be unreasonable to reject a terrorist group's peace treaty?

In a hypothetical situation.

If the terrorists bombed, drove down and axed civilians, stabbed them, shot down a seniors home, children's schools, surrounded the country's border and constantly announced their extreme hatred and desire to wipe out all USarians and broke the first peace treaty with missiles all resulting in shortage of food and water and constant air raids.

Would these terrorist's actions justify the USA defending herself and reject the peace treaty?

Wouldn't that be that be unreasonable? I mean, sure, those were horrible but imagine the damage the USA will cause! Completely evil, completely absolutely and definitely...

Oh, the hypothetical situation has the USA with no allies so nobody would help the them if they got attacked...

And the news would completely ignore your suffering to focus on your forever negatively viewed actions, even if it's self defense.

I guess self image might supercede safety...?