WASHINGTON.-- lt;U.P. —Military and naval experts, scrutinizing the Far Eastern situation and the possibility that China's Open Door” may be permanently closed to the western world, have indicated that the Philippines would be an important factor in determining the ultimate policy of the United States toward China.The Philippines, experts said, constitute an available hostage to the Japanese, if the western powers should seek to enforce protests against Japanese policy in China,The Philippines, on the other hand, might be a valuable military and strategic base whose strengthening would place the United States i. a potent position in the Far Eastern military picture.These factors are said to influence high government officials in mapping their approach to the Chiinese situation. It is extremely doubtful, informed sources indicated, whether any drastic steps v/ould be taken in the Far Eastern situation, until careful evaluation o: possible eventualities had been made.