Russian and Turkish forces have been clashing, turning the area of Northern Syria into a warzone and causing a massive humanitarian crisis. Russia backs the Assad regime, while Turkey backs the opposition rebels, and both are funneling military forces into the area.  The international nature of the Syrian crisis is what has caused it to become so out of control. Russia and Turkey are practically fighting a war through Northern Syria, turning the conflict much bigger than it would be. Countries such as Russia and Turkey need to stop sending military support into Syria, so the conflict can become more manageable and peace can be restored.
The ceasing of international involvement would be a disaster for Syria. Without the support of a broader global audience, Syria would not receive the funds or attention it needs. The crisis might be largely ignored and made much worse if international participants were to end their participation.
[P1] The Syrian crisis is escalated by international military involvement. [P2] Turkey and Russia are fighting a proxy war in Northern Syria. [P3] Turkey and Russia need to end their involvement to avert the crisis in Syria.
Rejecting the premises
[Rejecting P3] Turkey and Russia pulling their involvement would ultimately lead to less helpful resources in Syria.