This is just my opinion. If you purchase an herb that is certified to be organically grown, this gives you some assurance that the herb was grown in conditions more favorable than those grown with typical commercial care (mass-production and the kind of care that comes with, like use of geneticly modifed seed stock, chemical fertilizers, Roundup-like insecticides/pesticides, etc). More to your question, if you purchase an imported herb, chances are good it was passed through u.S. import/inspection processing, which is supposed to include - fumigation / radiation / and possibly one or more of a variety of other processes that are used under the guise of reducing the infiltration of undesirable foreign pests (fruit fly, worms/parasites, eggs/larvae of same, etc). These same processes that supposedly reduce/eradicate undesirable pests also devitalize the plant/herb's beneficial properties whether it was organically grown or not. As an example, even though I've never seen industrial fumigation in action, I've seen it on a small scale; putting off a bug-bomb in a house, which releases various kinds of chemicals, intended to kill pests. People who put off a bug bomb in their house are generally advised to not be in the house while the bomb is doing it's work. This suggests the fumigating chemicals may be harmful to other living organisms (like people) besides what are commonly known as bugs and winged pests.
Again, this is just my opinion. There are others here who have more knowledge on the "certified organic" issue and may give you a better or different answer.