the hard intellectual labor of sorting out Marty Peretz, Alan Dershowitz and Norman Podhoretz

Jack Ross writes:
Dershowitz is still, at least half-heartedly defending Obama–Commentary's take with a link to the column. I'm not sure quite what to make of it.  On the one hand, Dershowitz takes pretty much the same position as Norman Podhoretz, that Obama isn't any real danger to Israel proper, before he descends into the paranoid line about Iran and that any effort to accommodate Iran is an "existential threat".  On the other hand Dershowitz is clearly reluctant to go as far as Marty Peretz has in the last month, but at the same time clearly suspecting it will only be a matter of time.  I am genuinely puzzled as to what accounts for this difference.