It died

Come on.  We know what happened. Somebody assassinated it.  And if you don't believe it, look at the grass.

The sapling came from Belleau Wood, north-east of Paris, the location of a ferocious but pivotal battle in which 1,811 Americans died in June 1918 during the first world war.

[...]

Even at the time, the auspices were not good: jokes quickly spread on social media that Macron was trolling Trump over his environmental policies.

Once the cameras had departed, the tree was uprooted and placed into quarantine to avoid the spread of non-native diseases and invasive insects.

Gérard Araud, the then French ambassador to the US, explained the quarantine was “mandatory for any living organism imported into America” and said the tree would be replanted later. Images showed only a yellow patch of grass in the spot on the White House south lawn where the tree had been planted.

[...]

Now it appears the oak did not survive its time in quarantine. Its death was confirmed by a diplomatic source to Agence France-Presse. Just like the Macron-Trump love-in, it is no more.

  The Guardian

I can believe they didn't bother to try to keep it alive in quarantine, on the other hand, why is the grass yellow at the planting site?

Disgraceful.

...but hey, do what you want...you will anyway.