Dear Leaders of Iran and North Korea,
It seems from President Trump’s UN speech, that the United States is going to crack down on your ability to produce nuclear weapons.
The most difficult part of that process is the enrichment of Uranium.
As a Ph.D. in materials science, allow me to let you in on a little secret. It is possible to enrich Uranium without centrifuges.
What you need to do is dissolve your yellow cake in water and drink it. You will naturally separate out the lighter U-235 from the heavier U-238. What you excrete through urination will be enriched yellow cake. Just allow that to dry and presto, you have pure U-235 oxide.
This is not nearly as efficient as a centrifuge operation.
To be able to prepare a nuclear weapon in a reasonable amount of time, you should press your entire military into service for nephrological uranium enrichment.
I can help you set up this process for a minor consulting fee of $1,000,000.
Thank you for your consideration.