Labor

build barracks

and conquer other provinces.

increase moral

Take note of Manpower upkeep costs of the units you chose to build. The higher the daily Manpower upkeep costs the slower Manpower resources will replenish.

One can tell if a player is relying too much on Militia (MIL) or Infantry (INF) if the World Herald (WH) newspaper isn't reporting Infrastructure (IS) and Industrial Complexes (IC) or Air Bases (AB) being built in the same territories, which allow for a diversification of units.

Also, a neighbor with only ICs (or ICs & Barracks) won't have the mobility to respond well to an invasion from a neighbor w/ armoured cars (AC) and/or tanks.