Although it is the third world that is going to take the hit, the wealthy nations will bid up the price of oil to ensure they continue to get it, the poorer nations will be priced out. What is an annoyance in the west -- say needing to delay a major purchase or postpone a vacation or reduce expenses - translates to famine and deindustrialization in the global south.
Maybe it's not such a good idea to be waging war against major resource exporting nations, the US and Europe are now sanctioning about half of the global resource exporting nations, and the only benefit of this is higher prices in our domestic economies and China coming in to sign trade deals for discounted Russian and Iranian oil.
KSA also needs to lay off the Houthis and lift the embargo, it's long past time that they give up trying to control who runs Yemen.
Best thing we can hope for here is Trump sees an obvious way out of this: return the economy to a predicable machine, reduce spending, tax the ultra wealthy, and ditch tariffs. But I don't think much of that's likely to occur.
We're in unchartered territory in many ways. Good luck.