Here's the quote from his speech at CIA:
"We don’t win anymore. The old expression, “to the victor belong the spoils” -- you remember. I always used to say, keep the oil. I wasn’t a fan of Iraq. I didn’t want to go into Iraq. But I will tell you, when we were in, we got out wrong. And I always said, in addition to that, keep the oil. Now, I said it for economic reasons. But if you think about it, Mike, if we kept the oil you probably wouldn’t have ISIS because that’s where they made their money in the first place. So we should have kept the oil. But okay. (Laughter.) Maybe you’ll have another chance. But the fact is, should have kept the oil. " [1]
Claiming that Trump is against interventionism is just you projecting your own wishes and hopes onto the blank canvas of his mind.
[1] http://www.cbsnews.com/news/trump-cia-speech-transcript/