Imagine two kids at school who are both trying to be the most popular, the strongest and the smartest.
That's a bit like what's happening between the United States and China right now.
These two giant countries have the biggest economies in the world, meaning they make and sell more stuff than anyone else. But lately, they've been competing to see who has more power over the other.
Here's how it breaks down.
1. They still need each other's stuff
Even though the US and China don't always get along, they still buy huge amounts of things from each other.
China sells the US things like electronics, clothes and plastics. The US sells China things such as food and chemicals. Think of it like two rivals at school who still have to swap lunch items because neither of them has everything they need.
2. The US spends less on China than before
When you buy more from someone than they buy from you, you end up in a "trade deficit". The US used to have a record $418 billion deficit. But that gap has more than halved to $203 billion.
The US is now buying more from countries like Mexico and Vietnam instead.
3. China's oil needs
China needs enormous amounts of oil to keep its factories running and its people moving around.
It used to import about 13.2 million barrels of oil every single day. But a war involving Iran has cut off a big chunk of its supply, dropping imports to about 8.2 million barrels per day.
The US is trying to make this harder for China by passing new laws that could punish countries buying oil from places America doesn't like. These are called sanctions.
4. China's secret weapon: Rare earth materials
Here's where China gets to flex its muscles.
Deep underground, there are special materials called rare earths. These aren't magical, but they might as well be – they're used to make electric cars, wind turbines, smartphones and even military equipment.
China controls more of these materials than almost any other country on Earth. If China decided to stop sharing them, it could cause serious problems for the US and many other countries.
5. The military race
Both countries are spending enormous amounts of money on their armies, navies and air forces.
Together, the US and China account for 44 per cent of all the money spent on militaries around the entire world.
The US still spends the most, but China has been increasing its spending every single year since 2000 and shows no signs of stopping.
So who's winning this rivalry? The honest answer is that neither side has won yet.
Each country has things the other needs, and that's exactly what makes their rivalry so complicated.
