Did our early success with limited troops in Afghanistan lead us into the nightmare in Iraq?

I would have rather seen Afghanistan completely secured. It is such a large country that the limited troop left there over the past few years couldn't finish the job. Plus 92% of opium production comes from Afghanistan. Now it's flaring up again. Thats a hugh issue if you ask me. It's too hard to fight 2 wars at once. Never should have gone into Iraq.