What do you say of this" you are informed of terrorists in neighbouring country" is attack the only means?

I was just surprised at the ignorance and justification shown by US troops in Iraq when they launched an attack in neighboring Syria, Does having a mission in on one territory mean that you transgress the borders into another state. my little knowledge says that it creates fear in the mind of any person and state and will ofcourse fuel vengeance. isn't it high time that responsible people realise that respecting borders and people is important. the war on terrorism is important i agree, but that can be done by taking your neighbours into confidence. i am not a muslim but this seems insane. death does the same thing in any part of the world be it US or Syria