In vanilla Civilization VI and Rise and Fall, Patriotic War is the only policy that provides a Production bonus for support units. It's helpful if you have immediate need of Supply Convoys and Drones to support your ground forces or Anti-Air Guns and Mobile SAMs to repel an enemy air assault.
Every war fought by the people is, in a sense, a “patriotic war” (after all, other than religion, it is the most effective way to convince folks to kill each other). But in the 20th Century AD, the term patriotic war has designated those conflicts where, according to Communist doctrine, the proletariat has risen to defend itself against a foreign threat. More generally, it refers to a war to defend the homeland, or in this case, the “Motherland.” First applied to the general resistance by the Russian peasantry to Napoleon's invasion in 1812, it was more generally used to refer to the costly defense of Russia against Germany in the Second World War.