UPDATE 10/3/2016: On Oct. 2, 2016, the Colombian peace deal was narrowly struck down by voters, leaving Colombians in shock. Both sides have vowed not to go back to fighting, however, meaning an era of peace is still expected.
As of September 2016, there are no more wars in the Western Hemisphere.
Yep, that's what I said. Read it again if you need to. The entire Western Hemisphere — also known as 50% of the planet — does not have a single war zone.