WATCH: Economist uses 'Mean Girls' to explain Trump's tariff play — and it's perfect

Donald Trump's plan to impose tariffs on steel and aluminum imports caught people off guard this morning, prompting a steep drop on the stock market and grim counseling about how this type of move is exactly what started the Great Depression.

How to explain this to Trump?

One MSNBC analyst, Brendan Greeley, drew a parallel to Mean Girls.

"It's all a question of how much power the U.S. has in the international trade system," he said. "Up until about 2000, the U.S. was Regina George in the beginning of Mean Girls. We set the rules, everybody else lived by the rules, we chose who our friends were."

And then we invited "a new pretty girl" into the mix. That would be China.

"The question is, how do we respond?" he says. "We have a choice. We're choosing the wrong thing. Right now, this tariff, is lashing out in an indiscriminate way, as a way of proving our power again. And like Regina George in the middle of that movie, we don't have the power we think we do.

"Do we understand how much power Lindsay Lohan i.e. China has yet?" host Stephanie Ruhle asked.

You can catch his answer below.