Your grandfather should have been proud and you of him. Hurrah!
My son was 3rd ID and fought in Gulf War I, Desert Storm and I’m proud of him.
Oh we are all most proud of him. Sadly, he did not live long enough for any of his 11 grandchildren to know him personally (not related WWI, so far as we know, but he did pass away in his 50s of a massive heart attack).
God bless your son and all of your family!!