The US though is easily able to offset the decline in population with immigration. Unlike Russia the US government doesn't have to offer money to come fight their war or force minorities to the front lines to be bullet sponges like we have seen by Russia. 

It's more of making it official as part of the agreement the two had. And the US is having decline too. 

Hamstr

I'm not gunna lie solid click bait... The easiest way to shoot this down is that Saudi's want US military equipment which means they have to keep a hell of a lot of dollars for how expensive that is. Not to mention the US is the world's largest oil producer and is also going to operate under the USD... BRICS doesn't have a future with China facing a population cliff. Russia had its population cliff hit first and look at the mess they are in because sanctions aside its military equipment has been terrible compared to the West