What makes you think that walnut from France is no longer imported into the U.S.? It's a pain to post a link with my phone, but a quick search turned up 16 French hardwood suppliers and exporters from frenchtimber.com
Another quick search turned up 87 timber and lumber companies in France. The Rhone-Alpes area of France produces an annual average of 18,000 metric tons of thin shell walnuts, and the southwest region produced 38,500 metric tons of walnuts in 2015. France is second only to Romania in European walnut production, and France is 7th in the world for walnut production. Just as in California, when you grow mature walnut trees for nut production, eventually they are harvested for their lumber. And so long as there is demand, more will be planted. Since there is no restriction on imports of French walnut wood into the U.S. that I am aware of, I'd bet you can send them your dollars and they will sell you their wood and their nuts.
