Nicolas II abdicated and a provisional government led by liberals and moderate socialists was proclaimed.
However, the real power in Russia after the February Revolution was led by soviet´s leaders, who supported a policy of general peace regret by Germany and the Allies.
Against this background, the War Minister Kerensky wanted to make some allies with new Russian´s offensives, but by then, Russian officers could not induce their men to obey because of several reasons related to peace (movement known as bolshevism)
Many Bolsheviks and Anarchists, such as Lenin, helped to destroy the capacity of Russian capacity to fight and were exiled.
The summer offensive was a disaster and peasant soldiers deserted ”en masse” to join the revolution. Kornilov led a military coup supported by most of the generals and forces of the political right. It failed but had important consequences, for example, Kerensky´s reputation plummeted when it became clear he had supported Kornilov´s plans.
The USA declared war on Germany and consequently, joined world war I because of several reasons: They had signed the “suxess pledge”, a treaty that established that Wilson (US president) would maintain diplomatic relations with Germany unless the German government attacked passenger ships. German violated that treaty because attacking British ships could allow them to defeat Great Britain and also attacked American´s ships. It also joined World War I because “Zimmerman Telegram”( Telegram that Germany sent to Mexican government to secure they would help them to recover their territories lost in the USA if they help support them in World War I) was discovered by the British.