Trump is moving ahead with withdrawal of US forces from Afghanistan. This move alone is strong enough to get him a second term in 2020.
In US politics the peace candidate always wins. The candidate who promises to pull out of a war or a sitting President who actually does always wins.
Trump is playing the republican playbook as perfected by Nixon.
Nixon realized that Vietnam was not a competitor to US and withdrew from the Vietnam War. As a result he won his second term as US president. Nixon split the Chinese from the Soviets. And focused on taking down the Soviets who were the main competitors.
Similarly, Trump has realized that Afghanistan, Syria & Iraq are not competitors and is withdrawing from these 3 wars. As a result he will win his second term as US president. He is trying to split the Russians from the Chinese. And he is focused on China who is the main competitor.