Iranian protesters chant slogans as they hold pictures of Shi'ite cleric Sheikh Nimr al-Nimr during a demonstration against the execution of Nimr in Saudi Arabia, outside the Saudi Arabian Embassy in Tehran January, 3, 2016.

Here's all you really need to know if you're trying to figure out the oil market: Iran and Saudi Arabia are at war. Everything else is secondary.

No, Iran and Saudi Arabia are not in a head-to-head war on an actual battlefield. But they are at war just the same, and the battle is being fought with more intensity now, on more fronts, and with more proxies than ever before. And one of the fiercest battlegrounds is oil, where Iran's post-nuclear deal/relaxed sanctions re-entry into the entire global crude market has given Tehran a new weapon to against its rivals in Riyadh.