117 3 EFFECTS OF AIR WARFARE ON INTERNAL COMMUNICATIONS IN OPERATIONS IN SPAIN FROM JULY 1936 TO DECEMBER 1938 AND IN CHINA FROM JULY 1937 TO DECEMBER 1938. I.—INTRODUCTORY REMARKS. IN both Spain and China attacks on internal communications have been directed principally against railways. Consequently, this report deals primarily with attacks on railway communication, although attacks on other forms of internal communication are dealt with. 2. Care must be exercised in drawing definite conclusions which may have little or no application in the event of a major war between first-class Powers for the following principal reasons:— (i) In neither country are communications developed to the same degree as similar communications in major European countries, nor do they make the same contribution to the economic, industrial and national life of the people.