The Bolshevik grip on power was by no means secure and a lengthy struggle broke out between the new regime and its opponents, who included the Socialist Revolutionaries, right-wing "Whites" and large numbers of peasants. At the same time the Allied powers sent several expeditionary armies to support the anti-Communist forces in an attempt to force Russia to rejoin the world war. The Bolsheviks fought against these forces and against national independence movements in the former Russian Empire. By 1921, they had defeated their internal enemies and brought most of the newly independent states under their control, with the exception of Finland, the Baltic States, the Moldavian Democratic Republic (which joined Romania), and Poland (with whom they had fought the Polish-Soviet War).[101] Finland also annexed the region Pechenga of the Russian Kola peninsula, Romania annexed Northern Bukovina; Soviet Russia and allied Soviet republics conceded the parts of its territory to Estonia (Pechory and the right bank of Narva), Latvia (Pytalovo) and Turkey (Kars). Poland incorporated the contested territories of Western Belarus and Western Ukraine, the former parts of the Russian Empire (except Galicia) east to Curzon Line.

The Russian Civil War (1917–1921) was a multi-party war that occurred within the former Russian Empire after the Russian provisional government collapsed and the Bolshevik party assumed power in Petrograd (St. Petersburg).

The principal fighting occurred between the Bolshevik Red Army, often in temporary alliance with other leftist pro-revolutionary groups, and the forces of the White Army, the loosely-allied anti-Bolshevik forces. Many foreign armies warred against the Red Army, notably the Allied Forces, yet many volunteer foreigners fought in both sides of the Russian Civil War. Other nationalist and regional political groups also participated in the war, including the Ukrainian nationalist Green Army, the Ukrainian anarchist Black Army and Black Guards, and warlords such as Ungern von Sternberg.

The most intense fighting took place from 1918 to 1920. Major military operations ended on October 25, 1922 when the Red Army occupied Vladivostok, previously held by the Provisional Priamur Government. The last enclave of the White Forces was the Ayano-Maysky District on the Pacific coast, where General Anatoly Pepelyayev did not capitulate until June 17, 1923.

Oh... let there be not a war anymore for anything , hope all people will love peace.

In a civil war all will be under severe pressure, I remember my Dad saying about this, It was the most frightful days of his life.