After the military rebellion, the Republic was left with a decimated officer corps and a severely weakened army in the regions it still controlled. Since the army was unable to resist the rebellion, the fighting mainly fell to the militia units organized by the various labor unions. While army officers joined these columns, they were under the control of whichever organization had formed them. The militias suffered from a wide variety of problems. They were inexperienced and lacked discipline and unity of action. Rivalry between the various organizations exacerbated the lack of any centralized command and general staff. The appointed professional officers were not always respected. They also lacked heavy weapons. Militiamen would often leave the front whenever they wished. Republican officer Major Aberri said of the militiamen he encountered at the Aragon front: "It was the most natural thing in the world for them to leave the front when it was quiet. They knew nothing of discipline, and it was clear that nobody had bothered to instruct them on the subject. After a forty-hour week at the front they got bored and left it".