No Royal Wedding Invite For Obama’s

The President of the United States has been snubbed.  Invitations for Prince William and Kate Middleton's wedding have gone out and the leader of the free world was not invited.  The Queen personally sent invites to leaders of 40 other countries.The President and his wife, Michelle, will be guests of the U.K. during an official state visit in May.  Why the snub?  Your guess is as good as mine, but I'd bet even money it has to do with the cost of security to protect the American leader.  Still isn't the friendship England the United States share worth the added cost?