There is no proof that Iraq would be more stable if we left troops behind. Afterall there were troops there and there was a civil war going on, there was succession movements, there was terrorist attacks.It was stablle in 2011, even Barrack Obama said so, but then he pulled the troops and we have what we see now. Yes, Al Q was still around, which is why the troops should have remained.
That is not true. In 2011 AQ alone killed 133 people. Here is the rest: https://www.iraqbodycount.org/analysis/numbers/2011/ . Looks like to me over 4,000....What period are you referring to here? Iraq was 'stable' in 2011. There were 55 deaths al year and not all of those from terrorists. Hoow does that compare with three years later?
Clearly you are not claiming there was only 55 deaths...You are not familiar with the history of the area.