Maliki is probably one of the reasons why ISIS is doing so well. He stacked the Iraqi army with his political cronies after the US pulled its troops out. Competent, American trained officers were replaced with men who’s only interest was stealing everything that wasn’t nailed down. He alienated the Kurds and Sunni groups that had allied with the central government. Even as ISIS was starting to surround Baghdad, he kept ordering the remnants of the Iraqi Army into assault after futile assault against Tikrit. At the same time, he was completely paranoid about the Kurds, blaming them for this disaster and refusing to give them supplies, their share of oil money, or military co-operation.
The problem there, is that the government envisioned the new Iraq after US occupation ended as being a strategic counterweight to Iran, as it was in the 1980s. A divided Iraq couldn’t serve that role.
The Posse Comitatus Act only prohibits the use of the military without congressional approval. Congress has approved the use of the federal military to restore order before, like during the Rodney King riots.
Afghanistan is an enemy of Pakistan. Around a quarter of Pakistani territory is filled with ethnic Pashtuns. This was land carved off of the Kingdom of Afghanistan by the English back in the days of the British Raj. Pakistan and in particular the ISI have been working since the days of the Afghan civil war to keep that nation fractious and divided, in order to try and prevent Afghan revanchism. Indian support for Afghanistan is an indirect way to threaten Pakistan.
I’m a bit skeptical about that. The military was ordered to integrate in 1948, but the Army dragged its feet until the Korean War broke out. There, the Army was so desperate for troops, any troops, that trying to maintain colored and white unit differentiation proved too problematic. If integration was successful six years later, under far more trying and chaotic circumstances, why couldn’t it have been possible in 1944?