The insurance companies didn't try to make oil prices spike. The insurance companies were merely adjusting the price of their insurance given the new information regarding the heightened risk in the area. Trump, not wanting oil prices to spike decided to offer insurance at a SUBSIDIZED price, meaning the American public would be paying for the insurance to foreigners. It is a good move politically for the American government but not a good move for Americans in general but if the end result is that the USA captures significant market share in the insurance industry over the UK, then it'll have proved a good move overall. Technically, the USA government subsidizing insurance like this and offering it to foreigners is a type of "trade war" through "State Sponsored Dumping". The UK should respond by putting tariffs on the American insurance being offered such that the price after tariffs matches Lloyds for domestic purchasers then when the USA eventually sells insurance for the correct price given the risk (no longer dumping), the UK should subsidize Lloyds to offer cheaper insurance than the Americans to buy back the lost market share. Of course, I don't think there's anyone competent left in any Western government so... just watch the UK crash and burn, I guess.