Libertarians are always saying drug interdiction is an abuse of the commerce clause, but I have always maintained that the authority to interdict drugs comes from the same place as the authority to interdict Nuclear, Biological, and Chemical weapons.
Or do you dispute the idea that the Federal government has the authority to interdict dangerous substances, especially those coming from outside our borders?
Nope. Anything coming from outside the U.S. clearly falls under "commerce with foreign nations" and is within the intended scope of the Commerce Clause.
OTOH, if someone wants try to mine uranium in Colorado, enrich it in Colorado, and manufacture a nuclear bomb in Colorado, using equipment and parts all manufactured and purchased solely within Colorado, then it would not fall within Congress' authority under the Commerce Clause (although trying to detonate it clearly would, unless it is a really small nuclear bomb with no fallout).
Of course, even if the Commerce Clause does not apply, manufacturing, selling or purchasing any sort of weapon of mass destruction (even if entirely intrastate) would still fall within Congress' authority under several of the other enumerated powers in Article 1, Section 8 of the Constitution, including the power to "provide for the common defense" of the United States.
The point is that the Commerce Clause is not Congress' only enumerated power and it should not be construed so broadly that the other enumerated powers are moot and the federal government has the power to regulate every transaction.