I was recently watching a World War One docudrama-esque show (Our World War (BBC)) and, while patrolling and fighting to control Trones Wood, some British troops unexpectedly encounter the German enemy. Instinctively, a rifleman calls "contact" as the engagement begins.
Rightly or wrongly, the use of the phrase contact took me by surprise. It's a well known phrase and part of many Immediate Action drills in modern warfare, but it didn't strike me as one that would be in use during World War I.
For example, an American Vietnam Era combat handbook states:
This immediate action drill is used, defensively, to make and quickly break undesired but unavoidable contact (including ambush), and, offensively, to decisively engage the enemy (including ambush). When used in chance contact, men nearest the enemy open fire and shout, "Contact, Front (Right, Left, or Rear)." The patrol moves swiftly into line formation and assaults.
So, my question is effectively twofold: When did the use of "Contact" begin and was the use in this context anachronistic?