 After this the Spanish armies lost every battle they fought against the French imperial forces but were never annihilated; after battles they would retreat into the mountains to regroup and launch new attacks and raids.Guerrilla forces sprang up all over the country and, with the army, tied down huge numbers of Napoleon's troops, making it difficult to sustain concentrated attacks on enemy forces.The attacks and raids of the Spanish army and guerrillas became a massive drain on Napoleon's military and economic resources.