It's been a few years since the US invaded Iraq... Regardless, China's investment in oil production does not translate to consumption. About half of Iraq's oil was going to the US around 2004.
China gains power and influence in foreign nations through significant investment in infrastructure (often leading to enormous debt), which is going to result in significant long-term gains for China. The US approach is to smash the front door down and loot the place, then install a puppet who is hopefully loyal to them and won't be easily ousted.
I wouldn't want to be on the receiving end of either of them, but I know which one I'd choose if I had to pick one.
Just use your hyperfocus superpowers
/s