"We absolutely cannot drag the troops into a counterinsurgency operation!"
This is the report sent by the Military Department to all front-line units.
Counterinsurgency operations themselves are completely different from regular military operations, and experience from such warfare is hard to apply in regular military confrontations, even major powers can be dragged down by them.
Just like the Soviet Union, during the Afghanistan War, its military expenditure reached up to 5 billion U.S. dollars a year. We cannot deny that their "dissolution" was due to internal reasons, but the external drag was also a significant factor.
This is one of the reasons why Victor didn't completely occupy New Mexico and California. Leaving aside whether it can be fully captured or how much would be lost, these two states combined cover nearly 800,000 square kilometers. How much armed force would be needed for stability there?