No, the Israelis (probably) didn't assassinate Arafat

The BBC (where the tone has been, as you can surely imagine, far less skeptical) spoke to an expert in radiation detection that likened using the tiny fraction of Po-210 available on the body and extrapolating it back to the time of Arafat’s death to “a blind man holding the tail of an elephant and using the information to work out the size of the animal.”

“It is impossible to take any of this seriously,” Israel’s foreign ministry spokesman pointing out that the evidence “is not even pseudo-science. If Arafat had been killed by polonium, the entire area in which he was buried would have been affected. People working there would have been affected. It is a well-known site in the center of Ramallah. The environment in which he had lived would have been contaminated. How is it possible that now we find polonium, but the French hospital in which he died detected none at all?”

No one has given any plausible reason for why no other polonium was found.