I didn't say I had "a theory", or that I had any particular suspicions - I just said that it is perfectly reasonable for suspicions to be raised,just as it would be if analogous suspicions were levied at Russia.

The fact that they are in this case directed at the USA is completely irrelevant. The apparent technical problems in carrying out such an assassination are relevant, but none of us know enough to dismiss the possibility out of hand merely on those grounds.