He owes Putin and the Russians.
They hacked the DNC an delivered damaging emails for Assange to publish.
I'm sure they want more than a platform promise to look the other way on Russians moving on Ukraine. I'm sure they expect more for their $12mil investment in Manafort.
http://www.reuters.com/article/us-usa-election-trump-briefing-idUSKCN10R25TEdited by Webbster at 09:10:37 on 08/17/16