She was born in 2013 at the National Zoo in Washington, DC.

Here she is biting her foot.

Here she is in the snow.

And here she is in a jumbo-sized FedEx crate bound for a one-way trip to Chengdu, China.

Bao Bao left because she was never ours to keep.

Her parents, Mei Xiang and Tian Tian, came from China 17 years ago.

But they weren't a gift – they were a loan.

And that loan stipulated their offspring will also belong to China, as do almost all of the pandas in zoos worldwide.

Pandas' natural habitat exists entirely within the borders of one country.

And that means these animals are more than just mascots for China: they're also tools in China's global diplomatic strategy.

What China figured out as it kind of became more of an international power in the second half of the 20th century was that this was something it could use to its advantage.

Pandas have been part of Chinese foreign policy since at least the 1950s.

Initially, it was just kind of given in the same way that, you know, governments have usually given exotic animals to others. It gave pandas to its allies.

Then after pandas officially became endangered, and that looked kind of tacky, they started giving pandas as loans.

In return, the receiving zoos pay $1 million, per panda, each year in fees.

And if a cub is born, zoos paying extra "cub tax" of $400,000.

The thing is that China doesn't give pandas to any country that can put up the money for a loan; it's much more selective than that.

Researchers at the University of Oxford have noticed a correlation between panda loans and China's international trade deals.

So, in 2010, China realized that it needed to find more market capacity to buy salmon.

Their traditional trade partner, who was Norway, had been kind of... The Nobel Peace Prize had gone to a Chinese dissident. China didn't feel like rewarding that behavior.

So instead, they turned to Scotland, which also produced salmon, also produced Land Rovers, which was something else that the Chinese affluent class were interested in,

and so they inked that trade deal and a panda was sent to the Edinburgh Zoo.

But what China gives, it can also take away.

Consider the case of Tai Shan, Bao Bao's older brother from DC.

China had made it known toward the end of 2009 that it wanted to take back the panda Tai Shan.

It hadn't really set a date yet.

Officials at the National zoo asked China to extend his stay, but the answer was no.

Experts suspect a couple of factors were involved in that choice.

One, President Obama met with the Dalai Lama, who is a strong critic of the Chinese government and a fierce advocate for the independence of Tibet, which the Chinese government denies.

And second, the US announced an arm sale to Taiwan, over Chinese objections.

A week later, Tai Shan and another panda from the Atlanta Zoo were on their way to China.

It considers pandas as kind of another arm of diplomacy in the same way that, in the event of a diplomatic spat, one country might recall its ambassador or might impose economic sanctions.

China sees, or certainly appears to see, from the way that its agreements go, pandas as kind of a way to reinforce international relationships that it's building and that it wants to continue.

More recently, we saw China delay a panda delivery, following the disappearance of a Malaysia Airlines plane carrying 152 Chinese nationals.

In 2014, Malaysia was all ready to get its first panda. They had the enclosure ready at the zoo and all of that.

And the day of the panda's supposed arrival came and went

because the Chinese government was extremely frustrated with the Malaysian government's investigation of the flight, didn't feel that it was doing enough,

and so kept the pandas for another month or two as a way to demonstrate to the Malaysian government, that yeah, we've signed a regional trade deal with you,

we're interested in pursuing a relationship, but you're not making us super happy right now.

Currently, the US still has 12 pandas, including Bao Bao's new little brother, Bei Bei.

But future relations with China could change that.

It's entirely possible that, whether in a military respect in the South China Sea, or in a political respect with regards to Taiwan,

that China will find good reason to feel that the US is no longer interested in pursuing the kind of warm partnership that they've had.

So what that means for panda diplomacy is really anyone's guess.