“At the time a story circulated saying that Pompeo had advised against such military action, saying that it would neither deter the Syrians nor stop their violence, and that it would only aggravate an already complex Syrian conflict. As a result of these views, it is believed he was kept out of the meeting by Trump himself, who doesn’t like being told that he is wrong.”
Source: Pompeo will do Trump’s bidding with regard to the Middle East | Asia Times