Under Lon Nol (and with American assistance), the Cambodian Army was enlarged and reorganized into the Forces Armees Nationales Khmeres (FANK) and then launched into offensives against PAVN. Hanoi responded by launching "Campaign X", an operation to widen the buffer zones around its lines of communication. John Shaw, in his "The Cambodian Campaign" refers to "Campaign X" only in the context of military actions in South Vietnam. It is symptomatic of many American sources (as it was to the American leadership at the time) that Cambodia was only relevant insofar as it affected the conflict in South Vietnam. Using economy of force, as few as 10,000 PAVN troops routed FANK forces in western and northeastern Cambodia, taking or threatening 16 of the country's 19 provincial capitals and interdicting, for various periods, all road and rail links to the capital. They also kept a wary eye on U.S. and South Vietnamese forces, which they fully expected would take advantage of the situation.