Kohima perimeter sharply reduced by the fall of FSD Hill and Kuki Piquet to Japanese attacks
Punjab Regiment with armoured support makes contact with the Kohima garrison
Japanese encirclement broken by 2nd Division under Major General Grover
Throughout the night of 17/18 April the Japanese at last made some serious progress. They successfully stormed FSD Hill and Kuki Piquet, effectively reducing the garrison’s perimeter to an area of less than 400yd (365m) in each direction. If the perimeter had been cramped before, it had now become desperately crowded with combatants, non-combatants and wounded men, as well as being thickly spread with dead Commonwealth and Japanese soldiers and the general detritus of battle.
On the morning of 18 April, however, the first encouraging signs of relief appeared when elements of 1/1 Battalion the Punjab Regiment, with armoured support, at last made contact with the garrison. The men of the Kohima garrison could now be withdrawn from their positions, but the battle was far from over. Desperate attempts on the part of the enemy to finally over-run the remaining perimeter before a full relief could be effected failed to make any headway, but the Japanese were still in position on and around Kohima Ridge and, as long as they remained there, the road to Imphal would be vulnerable.
In the early stages of the battle, 2nd Division had been assigned to the protection of Dimapur. As a whole, the division had no experience of fighting the Japanese. Although elements of 6th Brigade had seen action in the Arakan in 1943, a large proportion of the brigade had been replaced since then. All of the 2nd Division had, however, been trained for combat in Burma. In early April 161st Brigade made its way into Kohima as a relief for the garrison, while two battalions of 5th Brigade – the Cameron Highlanders and the Worcesters – got ready to close the Kohima to Dimapur road. By 17 April a series of hard-fought encounters had restored contact with the balance of 161st Brigade at Jotsoma. Once the Kohima garrison had been replaced, Gen. Grover, commander of 2nd Division, was faced with the problem of destroying Japanese forces which were, by this time, well entrenched in the surrounding hills. His plan was to ensure that the Japanese were engaged at every point of the battlefield and would, therefore, be unable to reinforce positions by moving troops across their front from one location to another. The general Japanese approach to defence in close country was not to attempt to hold a continuous line, which was effectively impossible in the jungle anyway, but to maintain a large number of well-protected positions and mount aggressive patrolling operations between them to discourage enemy penetration.
Map 5 Kohima Ridge. (Butler, p.347)
This had proven to be an effective approach in the past. Although the individual posts could become isolated and fall to the enemy, so long as the occupants were determined to sell their lives dearly, each post would have to be pounded furiously and then stormed in a close attack, which inevitably caused heavy casualties. In the main these posts were very small, containing only a section or platoon of men, but could absorb the attention of a whole company of enemy infantry for days on end. Fighting of this nature had a damaging effect on the morale of the Commonwealth troops charged with destroying such positions. Hard fighting with heavy casualties, only to find that the objective had only housed a handful of Japanese soldiers in the first place was bad enough, but the realisation that exactly the same sort of objective had to be faced on the next slope, and the next, sapped the spirits of the soldiers. As if that and the gruelling conditions of jungle warfare were not hard enough to bear, the aggressive patrolling of the Japanese between their defended localities meant that the troops could never be at ease since a Japanese patrol might fall on them at any time of day or night.
31 Shattered houses on the Kohima battlefield. (AB/AWH)
Although Commonwealth troops enjoyed major material advantages over the Japanese in terms of armour, air support and artillery – and a huge advantage in ammunition supply and radio communication – much of this was negated by the terrain and weather, and by the close proximity of the enemy forces. Often there would be only a short distance between the frontline troops and the cover afforded by the forest canopy; and the torrential rain frequently made observation with guns or the provision of air support by fighter-bombers of the RAF and RIAF virtually impossible.
Equally, the rain did hamper the Japanese as well. The downpours had much the same dispiriting influence and exacerbated the challenge of getting ammunition and food to the outposts, but at least the majority of the men were under cover – though it made strongpoints and bunkers prone to a degree of flooding.
General Grover’s division did not fully concentrate at Dimapur until 11 April, though elements were probing Japanese dispositions by the 9th. His general plan intended not simply to eject the Japanese from Kohima, but to pin 31st Division in the mountains and destroy them completely. To this end, he planned to send 4th Brigade (Brig. Goschen) to the south of the Japanese line while 6th Brigade (Brig. Shapland) pressed in the centre to dislodge the enemy from Kohima Ridge and 5th Brigade (Brig. Hawkins) moved to cover the Japanese from the north.
32 Commonwealth troops on the march. (AB/AWH)
The point unit of 5th Brigade reached the Kohima to Merema road on 18 April and were followed by the rest of the brigade over the next week. This proved to be an exhausting manoeuvre, but one that was achieved without loss, and by the late evening of 26 April Hawkins’ force had concentrated on Merema Ridge and was preparing to advance on the Japanese positions.
While the Commonwealth troops faced a major challenge in assembling and moving to suitable locations for the coming battle, the Japanese commander had problems of his own. The volume of supplies he had been promised for the campaign – a minimum of 10 tons per day had failed to materialise and he now faced additional demands on his depleted force. Early on 21 April a lone Japanese NCO was shot off his bicycle on the Merema road and was found to be bearing orders that 1st Battalion of 138th Regiment was to disengage, pass to the south of Kohima and march to join 15th Division in the battle at Imphal. These instructions had already been received by Gen. Sato, although he had made no effort to fulfil his instructions. Sato’s division had suffered heavy casualties in the Kohima fighting and if he were to achieve any of his objectives – the most important of which was really to take Dimapur, though he had chosen to focus his efforts on Kohima – he could hardly hope to do so if his strength was reduced at all, let alone by a margin of one out of his nine infantry battalions. In addition to losses on the battlefield, his command was now struggling with food shortages, which in turn made his men more susceptible to disease. Although 31st Division had brought several large heads of cattle to provide beef on the hoof, the majority – perhaps in excess of 80 per cent – of the animals had died during the march to Kohima through exhaustion, dehydration or in falls from precipitous mountain paths. The lack of beef forced units to slaughter their mules for food, which in turn reduced their ability to secure food, medicines and ammunition from the available stores. By the time the division approached Kohima, many of the troops had contracted malaria and many more were suffering from dysentery.
His repeated demands for resupply met with refusal and it was now abundantly clear that he could not hope to renew the attack on Kohima, let alone advance on Dimapur, despite the fact that a successful attack on the latter was crucial to any remaining hopes of a major Japanese victory.