"That quote is totally out of context, and probably doesn't mean what the headline says."
That's exactly what he said.
Speaking to Channel 4 Straw said: "If you want to see a nuclear-free Middle East, you've got to remove that threat from Iran, including the rhetorical threat to wipe Israel off the face of the map. Once you've done that, then we can get on to work in respect of Israel."
I don't take that to mean that once Iran's nukes are gone it's time to disarm Israel. He said you have to remove the threat from Iran, including its rhetoric about wiping Israel off the map, and then "get on to work in respect of Israel," which like i said, probably just means dealing with the Palestinian situation. That said, we'd probably have to see a transcript to be sure.