In the Black Sea, Russian cruiser Pamyat Merkuriya, accompanied by two destroyers, lowered four minelaying launches and a motor speed boat, which laid 120 mines north of the mouth of the Bosporus which went undetected by the Turks. An attempt to repeat the operation the following evening was broken off by an attack by two German aircraft. In Northern Persia, Kurdish tribesmen attacked the Russians near Khanikin.

On 18 May, at Petrograd, the Provisional Government collapsed. A.I. Guchkov resigned as Minister of War. He was replaced by former Minister of Justice, Alexander Kerenskiy. Guchkov then replaced Admiral I.K. Grigorovich as Naval Minister.

Milyukov resigned as Foreign Minister and was replaced by Mikhail Tereschchenko. The Duma urged the new Provisional Government to remain loyal to the Allies. The Provisional Government was reorganized and became a coalition in which the Soviet now allowed its members to participate. Beginning of the First Coalition Government.

At Minsk, General Denikin replaced General Gurko as commander of the Western Front. Denikin's Chief of Staff was General S.L. Markov.

On the Romanian Front, French General Henri Berthelot arrived at Bacau.

On 18 May, on the Macedonia Front, Russian General Diterikhs noted growing resentment among troops of his 2nd and 4th Brigades. In July they were organized into an independent division. During August, General Diterikhs returned to Petrograd. His replacement, General Taranovskiy only arrived in early November. By that time the unrest had increased. During January 1918 some 3,000 Russian troops mutinied near Vertekop, which was quickly put down by force.

At Kiev, opening of a three day First Ukrainian Military Congress, with some 2,300 delegates attending.

On 19 May, at Petrograd, Soviet Commissars were made responsible to the Provisional Government.

In the Baltic Sea, ice conditions in the Gulf of Finland finally allowed Russian submarines Bars, Gepard, Vepr and Volk to sortie. They scored no successes along the Swedish coast, but lost the Bars, probably on the 28th, by German depth charges in Norrköping Bay. The Russian account stated she was rammed and destroyed in error by a Russian destroyer north of Dago Island.

On 20 May, at Mogilev, meeting of a Congress of Officers under the auspices of the First Officer's Union, an alliance of over 300 army and navy officers. After the Bolsheviks took power in November, many of these men would form the nucleus of anti-Bolshevik forces.

At Petrograd, the Provisional Government announced that it recognized its debt of honor to the Allies and repudiated any peace talk.

In the Baltic Sea, Russian minelayers laid 4,463 mines to extend various mine barriers in key defensive positions. By the end of September, another 1,866 mines had been added to these fields. The Russians did not carry out any offensive mine-laying operations during the course of the entire year.

In Washington, the U.S. Government granted Russia a line of credit of $10,000.000.

On the Allied Western Front, first of a series of mutinies by French troops with whole regiments refusing to go into the front lines. On 1 June, the French Army had to order a cessation of all actions, with the High Command struggling to hold the army together. Over 23,000 men were eventually court-martialed, about 50 mutineers were executed.

On 22 May, General Polivanov issued Order No.8, the Declaration of the Rights of the Soldier, which gave them the right to join any political organization, freely express all political and other views, receive all printed matter addressed to them, and abolished the compulsory saluting of officers.

At Petrograd, the Bolshevik newspaper Pravda (Truth) published Lenin's article urging fraternization as a means of accelerating the proletarian revolution throughout the world. In Budapest, resignation of Count Tisza, Hungarian Prime Minister.

On 23 May, at Odessa, opening of the First Congress of the Soviets of the Romanian Front, Black Sea Fleet and Odessa Military District. General Shcherbachev addressed the Congress, stressing that victory was necessary to carry out and secure reforms and that to do this, discipline must be restored.

At Jasi, the Romanian calendar was ordered changed to the Gregorian (Western style).

On the Southwest Front, Kerenskiy, the newly appointed Russian Minister of War, began a tour of the front which lasted until 2 June.