Anyone can Google "u.s. atrocities in vietnam"...
The Internet is full of opinions and insights that can be searched via Google. What is your point? It can be argued that any nation engaged in war commits atrocities. Some would argue that killing US Citizens without due process is a "US atrocity".
Back to Kerry, his actions and comments sold out US soldiers. His comments were targeted at The Troops. You cannot be an effective Military Leader if you are constantly throwing your subordinates under the bus. He did this with Vietnam and Iraq.
Kerry held US military to their own rules, rules that some of the military were not following. As others stood by, Kerry spoke out, and if some had spoken out earlier there may not have been a My Lai or other shameful deeds. Sure Kerry was what ever names you want to call him, stoolie whatever, but he tried to hold the military to their own regulations and the regulations had a purpose, if some have to be thrown under the bus for committing atrocities, so be it. Sometimes committing atrocities on the enemy can come back and bite some of your own, that have not committed atrocities.
Military men in the past have discovered that no matter their rank, private to general they are required to follow military rules, ask MacArthur, Slovick and now Patraeus.