Some general observations on the Burma war in WWII might be helpful - not that I hold myself to be any kind of a military authority - In the first place, references to being "behind enemy lines" need qualification.
Burma and Siam (the old name was in use during WWII) are big places (combined land area 458,487 sq. mi.) Over this the warring armies roamed, much as in the medieval wars in Europe, with scant regard for the inhabitants. We had observed Siamese neutrality (as with Goa in India), but the Japanese invaded it on their 1942 advance North, so Siam was fair game after that. The ordinary Burmese and Siamese had no dog in this fight: I suppose they looked on it as simply White Sahibs fighting Yellow Sahibs for control of their lands and devoutly wished "a plague on both your Houses !"
It follows that there would be on the (southern) Japanese side large areas where there were no Japanese troops, and on the (northern) Allied side large areas where there would be no Allied ones. As you approached the battle areas, the numbers of combatants per sq. mi. would build up until you reached the "Front Lines" where troops were actually engaged.
These "Front Lines" were not contiguous. Arakan was a level, narrow coastal plain between the mountains and the Bay of Bengal up which the Japanese pushed: it was obviously the way to Chittagong (deep water port and a paved runway). Control of Chittagong would greatly simplify the Jap supply problem and it was one obvious springboard for the invasion of India (with Calcutta (on the other side of the bay), ripe fot taking - if you could get across the "Sunderbans" - the vast tidal delta of the Ganges and Bramahputra rivers.
Further North and East; the state of Manipur (Imphal and Kohima) in Assam, the geography offered another way of attack fom the central plain of Burma West into the Silchar valley.
Google: ...war map of the Manipur region in WWII...(scroll down to) ...Battle of Imphal-Kohima | World War II Database... (scroll down to).....Battle of Imphal-Kohima Interactive Map...
You can see the high road into (present) Bangladesh (then) "The North East Frontier Province" - and as it's well North of the Sunderbands, it's a straight walk to Calcutta (and there were railways).
Further North still, there were the Americans (General "Vinagar Joe" Stilwell) and "Merrill's Marauders" and Chennault with the "Flying Tigers", but they were less concerned with keeping the Jap out of India than of keeping Chaing Kai Shek and China going in their war with Japan.
So what's all this leading up to ? First, it explains how many of our "bale-outs" over Jap held territory walked back out without even seeing a Jap. And (without belittling their achievements in any way) how Orde Wingate and his Chindits, Force 136, (and John Dunbar et al) were able to achieve what they did. (Could a 'Chindit' style operation have been mounted in Europe ? - Impossible !)
Danny.