This paper develops a distributed algorithm of decision/awareness propagation in mobile agent systems with a time varying network topology and threshold based agent interaction policy. While message broadcast duration or state updating interval is found to be an actuation parameter for changing time-averaged network topology, the threshold parameter in binary decision policy can be used to trigger or restrain the decision propagation. The influence of (large) seed size on the propagation phenomenon has been exploited to control the threat level threshold, beyond which the awareness propagates throughout the network.