Decion-making is the most critical phase in Observe, Orient, Decide, and ACT (OODA) defense decision cycle. If the decision made is correct regardin tyhe current situation, then it can minimize the possibility of loss. The contradiction situation will accur if the incorrect decision is made. The correctness of the decision depends of the quality on information delivered from orient (ation) phase that will be used as the basis for decision-making. Meanwhile, in defense aplications the prcess of decision-making plays a very important role espcially if the time is the most affecting factor. Such an application is nation defense system in defending our country's nation sovereignty in air, sea, and land. Therefore, the faster the decision is made, the earlier the system can perform anticipations to any nation defense intrusion. For this purpos, in this paper we addres the utilization of A3S (Arwin-Adang-Aciek-Sembiring) information-inferencing fusion for accelerating the information processing and obtaining good comprehensive information quality that will be used as the basis for strategic decision-making for nation defense.