Wasp or Hornet

I was trying to take photos of this bee on my butterfly bush, but it kept going inside the bunch of flowers. While I was waiting for him to come back out, this bug came flying in, attacking my little bee. I hit the remote shutter and the flash went off, sending the attacker flying somewhere else. Any idea what this thing is? The second photo is the only photo of the bee that even halfway turned out. Should've taken pictures of the monster mosquitoes that were feasting on me instead.