Towards the end of April preparations were begun for a second raid across the Jordan. After the failure of his attack on the Ghoraniyeh bridgehead, the enemy had largely increased his forces east of the river, and had improved and strengthened his entrenched position at Shunet Nimrin. At the end of April he had about 8000 troops occupying this position. General Allenby determined to try to cut off and destroy this force, and, if successful, to hold El Salt till the Arab forces could advance and relieve our troops.
The great German offensive in France in March and April resulted in the force in Palestine being called upon to send to Europe every man and gun that could be spared. Thus, during April, the Yeomanry Division and two infantry divisions, besides ten other infantry battalions and a number of siege batteries and machine gun companies, were withdrawn from the line, and embarked for France. These troops were replaced by Indian regiments, the Yeomanry by Indian cavalry from France, and the infantry partly by the Lahore Division from Mesopotamia, and partly by untrained native troops from India.[20]
It was originally intended that the raid should take place about the middle of May, when the reorganisation had been completed, and the full strength of the Desert Mounted Corps would have been available. A necessary part of the raid, however, was the co-operation of the powerful Beni Sakhr tribe of Arabs, numbering some 7000 fighting men, which was at that time in the district round Madeba, about twelve miles east of the north end of the Dead Sea. Towards the end of April this tribe reported that their supplies would be exhausted by the 4th of May, and that they would then have to move to their summer grazing grounds farther south. The Commander-in-Chief therefore decided to attack at once, without waiting for the arrival of the Indian troops, though, in doing so, he was compelled to carry out the operations with a considerably smaller force than would have been the case if he had been able to wait another fortnight.
Thus the troops available for the raid consisted only of the Anzac and Australian Mounted Divisions, with two brigades of the 60th Division, and the (Indian) Imperial Service Cavalry and Infantry Brigades.
There was good reason for the employment of this large proportion of cavalry in an operation that was to be carried out in country most unsuited for mounted work.
General Allenby was always reluctant to keep his mounted troops in the trenches, if he could avoid doing so. Cavalry are most uneconomical troops in trench warfare, since at least a quarter of them are occupied caring for the horses, and consequently are not available for the firing line. Moreover, while employed in the line, they are deprived of the opportunity of training for mounted work, and their horses generally lose condition, since there are not enough men to look after them properly.
When, however, the three cavalry divisions were not used in the trenches, there were barely sufficient troops left to hold our long line securely, and very few infantry could be spared for extraneous enterprises. Moreover, though he would not put his cavalry into the line, if he could help it, the Commander-in-Chief had no intention of allowing them to grow rusty for lack of active operations. He was a firm believer in the old prize-ring adage that the best training for a fight is fighting.
The enemy's position ran north and south, astride the Jericho-Amman road, just west of Shunet Nimrin, his left resting on the deep gorge of the Wadi Kefrein, and his right flank thrown back in a half circle across the Wadi Arseniyat track to El Haud. Both flanks were protected by detachments of cavalry. From Shunet Nimrin two roads led back to Amman; the metalled road through El Salt, and the more direct track through El Sir. The former was the only one available for wheeled traffic, but the latter had been considerably improved by the Turks since our last raid into Gilead. The plan was for the infantry to attack this position from the west, with the New Zealand Mounted Brigade on their right flank, while the rest of the cavalry, moving along the east bank of the Jordan as far as Umm el Shert and Jisr el Damieh, turned into the hills up the tracks from these two places, and captured El Salt, thus cutting the road to Amman. The Beni Sakhr Arabs undertook to hold the Ain el Sir track. With their only two lines of reinforcement or retreat thus closed, there appeared to be a good prospect of capturing or destroying the enemy forces at Shunet Nimrin.
In order to prevent the enemy from transferring troops from the east to the west bank of the Jordan at Jisr el Damieh, as he had done during the previous raid, one brigade of cavalry, the 4th A.L.H., was directed to seize the Turkish bridge at that place if possible. If, however, it proved too strong to be taken, the brigade was to take up a position covering the track to El Salt, and endeavour to prevent the enemy crossing the river.
Our force crossed the Jordan on the night of the 29th of April, and by dawn the cavalry were through the scrub on the east bank, and advancing up the narrow plain between the river and the mountains, led by the 4th A.L.H. Brigade. The 1st and 2nd A.L.H. Brigades were attached to the Australian Mounted Division during the operations.