A week later, on March 16, the Tsar abdicated.

Obviously, it was a last attempt on his part to save the situation which, had it occurred a few weeks earlier, would not only have altered the fate of Russia, but that of the whole world.
The Russian Revolution placed us in an entirely new situation.

After all, there was no doubt that the East presented an obvious possibility of concluding peace, and all our efforts were turned in that direction, for we were anxious to seize the first available moment to make peace with the Russian Revolutionary Party, a peace which the Tsar, faced by his coming downfall, had not been able to achieve.
If the spring of 1917 was noted for the beginning of the unrestricted U-boat warfare and all the hopes centred on its success and the altered situation anticipated on the part of the Germans, the summer of the same year proved that the proceeding did not fulfil all expectations, though causing great anxiety to England.

At that time there were great fears in England as to whether, and how, the U-boat could be paralysed.

No one in London knew whether the new means to counteract it would suffice before they had been tried, and it was only in the course of the summer that the success of the anti-submarine weapons and the convoy principle was confirmed.
In the early summer of 1917 very favourable news was received relative to English and French conditions.