Nothing wrong with Sen. Kirk’s actions. Assurances given by a liberal Democrat should be treated with suspicion (and when warranted, hostility) by Republicans. Wendy Sherman has a different way of viewing the world than Sen. Kirk and he feels her way is badly flawed (I agree with him, BTW).
Moreover, it would foolish for any Republican senator to agree with the Obama administration over the Israelis when it comes to Iran. Doing so emboldens Iran, supports an administration that has proven irresolute where Iran is concerned, and alienated that senator from him party.
Mark Kirk is right and Wendy Sherman is wrong.