The bills will strengthen Japan, U.S. and other friendly countries alliance. And that will prevent huge conflicts because no one wants to fight. Moreover, the bills limit Japan's activities.
An evil country just want to force other countries to obey their rules. They think only military power can do that and that's the reality in the world. They don't need fight against others. Only they should do is to show their power to others. But they will be careful when other countries also have a strong power because the evil countries don't want a war to break out, but only small conflicts. They definitely afraid of real war. These security laws can control their desire to expand their territory.
To have power doesn't mean goes into a war. If a nation alone has enough power to protect itself from evils, there wouldn't need military alliance. No need to rescue others instead of to be protected by other nations. But the reality doesn't let us so.
Looking around Japan, evil totalitarian countries have a long history of cruel behavior. They can't stop doing so unless the governments have replaced democratic one.