(Photo: Denny's) In a running marketing battle in which leading chains have promoted the cause of making hybrid burgers in the name of peace, McDonald’s is trying to get the last—and most substantive—jab in this tiff with Burger King. McDonald’s wasn’t willing to bite on a Burger King proposal to join forces in making a “McWhopper” in the name of promoting peace, but executives at the Golden Arches said on Sunday they are leading a “multi-million dollar” advertising campaign to promote the United Nations World Food Programme and benefit refugees of conflicts in Syria, Iraq, South Sudan and Yemen. The 30-second television and is the latest turn in the back-and-forth between the two fast food giants that started last month when Burger King proposed in a advertising campaign that the two burger makers get together to make a “McWhopper” (a cross between the Big Mac and Whopper) at... More