A 40-year old Montana man was killed over the weekend after getting in an argument with another man about which branch of the military was the best.

William Earl Cunningham, 63, of Laurel, Montana, is charged with deliberate homicide for slashing the throat of Nathan Horn of Billings, Montana. Cunningham told police he and Horn were in an argument over which branch of military was better, the Army or Marines, the AP reports.

Documents from the case said Cunningham told police he and Horn were arguing when the younger man jumped up and took a swing at Cunningham. Cunningham said he then did what he learned in the Army and slashed Horn.

Horn was pronounced dead about an hour later. Police said the men had argued about the same topic the previous night.

Cunningham is being held on $500,000 bail.