Politicans or Murders

Why is it we go to war,such as what is happening over in Yemen,or any other country to kill the people over oil,or land that is rightfully the ownership of the people that reside there!The problem is we have been allowing this to go on for too long!Look at Libya,there was no reason to go into that country and kill their leader Guaddfi,and now they sell people into slavery.Thanks to the past President Obama,and now look at what is happening to the new President Trump,lier,lier !Can we entrust our Presidents to promote peace around the world?