When the trustee whose powers have been suspended as aforesaid shall cease to be engaged in war service, as determined by the court, and any of the duties of his office shall not have been fully performed, the court shall, on petition of such trustee or any person beneficially interested in the trust of which he was a trustee prior to such disability, or any person having an interest in the subject matter thereof by way of remainder, issue an order terminating the suspension of his powers, restoring all of the powers possessed by him prior thereto, and removing from office any trustee who may have been appointed to serve in his place and stead.