Yerevan, Armenia, HQ of the Transcaucasian front
Transcaucasian front consisted of four armies - 47th, 53rd, 29th and 30th. Two of those, 29th and 30th would attack into Iraq and southeastern Turkey, one (53rd) would attack towards Tabriz and one (47th) towards Trabzon.
The most important axis of attack would be the advance down the rivers of Euphrates and Tigris. Budyonny plans were to reach Mosul in two weeks and Baghdad in three with his central force. From there to Basra would take another week, according to the plans of his staff, thus bringing the entire campaign to conclusion in a month.
Attacks in other directions were expected to take a similar amount of time. The advance to Teheran would take his 47th Army less than fortnight and, unless the situation changed and made further advance unnecessary, another month and a half to reach the Straight of Hormuz. Meanwhile, an advance towards Tabriz and subsequent capture of the city would threaten Ankara and force the Turks to cease hostilities.
At the spearhead of each army was a cavalry corps, while four mechanized corps formations were designated as reserves and would follow up the cavalry in order to occupy territory and secure against any possible insurections or counterattacks by the Allied forces, as well to mop up centers of enemy resistance the cavalry was to bypass.
The Front was supported by the 3rd Air Army, whose airplanes took off at the first sight of light on the morning of May 15th. Of the 450 aircraft allocated to the 3rd Army, 350 departed towards their targets in Iraq. The rest deployed to protect the airfields against possible attack by Allied air forces.
At approximately 4 o'clock, the thunderlike rumble of the Soviet artillery announced the beginning of the Soviet offensive into the Middle East.
Cairo, Egypt
The reconnaissance reports from the previous week caused serious concerns in the Middle East Command. It was obvious the Soviets have amassed troops in Armenia, Azerbaijan and Georgia. Countless trains have been recorded in transit across the few railroads leading into area and a few Soviet airplanes were intercepted, no doubt in reconnaissance missions.
The trouble is General Wilson, now in command of the theater, had almost no forces to deploy against this threat. The two divisions in Egypt and one in Palestine were held as a general reserve for the troops deployed in Crimea. The French also held two divisions in Syria and Iran possessed a military 120.000 strong, though of questionable quality. Turkish Army also deployed some of its military on the eastern border and expected to be able to defend for some time, given favorable terrain.
Then, the news came that the Red Army has initiated the offensive. Simultaneously, air bases in Iraq came under attack by the Soviet air force. While there were two squadrons of Gladiators in the air, they were unable to stop the large Soviet bomber formations. Despite the inaccuracy of the bombing, the air bases suffered a lot of damage, and a number of aircraft were damaged. Fortunately, dispersion of the bombers worked and out of more than 150 bombers, only 20 were damaged beyond repair. The runways were cratered, but it was easy to fix.
It was the ground offensive that really worried the British. The Soviet formations quickly overwhelmed weak defensive line and advanced over 20 km within the first day, despite the very inhospitable terrain.