Why did Schroen roll the jeep into the lake at the end of Chapter One?

Schroen rolled the Quaid-I-Azam University jeep into the lake to hide it as he could no longer drive it to meet agents clandestinely once it had more or less been reported stolen. The rioters had burned all the cars at the Islamabad embassy and the CIA station lacked mobility. Schroen hot-wired a university jeep that had apparently been left near the embassy by the rioters and which he used until officials came to recover it. That was when Schroen decided the best move was to abandon it.