In some languages and situations, "army" is a general term for the military or for a military force. In other languages and situations, it refers specifically to ground forces. Americans are usually in the latter camp, especially if they have a connection to the military.

No offense, just stating the truth. Only someone who has never been involved in a legal argument thinks that kind of "pedantry" is good for something.

Try to "aschkually" a judge irl and you'll find out. Hilarious.

I meant that the person writing the contract must be a pedant. Vague everyday language can only lead to bad things, when someone inevitably interprets in a different way.

In this particular case, the bets were clearly about military operations with the intention to take control of Venezuelan territory. This is the established meaning of "invasion", in contexts where people care about distinguishing between different types of military operations. But because people could plausibly interpret the word in a different way, the rules did not use words "invade" or "invasion" at all.