Poisoned World

Life in the remaining major cities.

In a word, it's tough. It's almost impossible to be on the streets without a gas mask. Every building is sealed off and equipped with a powerful air filtration system to filter out toxic substances. The streets are patrolled either by combined volunteer units (druzhina) or by soldiers.

Inexplicable

Beginning in 1926, strange phenomena began to occur along the front lines. There were reports from the Altai Front of the appearance of a group of soldiers who appeared to be dead. There are no photographs.
The air temperature in some places dropped abnormally quickly, then rose just as sharply. A man, alone and without ammunition, withstood an attack by an entire enemy company, and so on. Some see this as a manifestation of God's will.

February 1931. The front as such ceased to exist. State institutions disintegrated. All that remained were isolated towns, whose populations had moved underground, and small settlements in the few places untouched by the war.

The world is divided into three zones. Green represents habitable areas. Chemical poisoning is either completely absent or minimal. Flora even grows. The largest remaining human settlements are located there, as well as the few remaining governments.
Yellow zones are places barely suitable for habitation. Being there without protective equipment is dangerous to your health due to contamination from chemicals or bombs. People still live there, but it's hard to call it life.
Red zones are places where even with protective equipment, access is difficult. They contain high concentrations of toxic agents or unexploded ordnance. These are areas where the Front recently passed. Life there is essentially nonexistent—everything has been scorched by chlorine, mustard gas, and sarin.

The technological level is the beginning of the 20s of the 20th century with some inclusions of technologies from the late 30s.

The main remaining state entities are:

Germany – the remnants of the German Empire, organized in the region of Prussia and Brandenburg. Led by a military junta led by Erich Ludendorff.

Kaiserstadt - a small group of Wilhelm's supporters, concentrated in the region of Schleswig-Holstein and Lower Saxony.

Russia – the government headed by Savinkov. He governs Petrograd, Karelia, and small areas around it.

The Soviets were a unified group of Red Army partisan detachments organized around Moscow. They were led by Lavrenty Beria.

The French state maintains its defensive position in the Orleans region. It is confident that German forces are continuing their offensive. Ferdinand Foch is in command.

England is one of the few countries that remained almost intact. However, it lost its colonies. The current king is George V.

The Vienna Government is the remnants of Austria-Hungary. King Charles I.

The Great War did not end in November 1918.

After the signing of the Treaty of Brest-Litovsk, civil war broke out in Russia. Germany supported separatist movements in western Russia, while the Entente supported the White Movement, whose offensive on Moscow in 1918 was successful. Having regained power, the Russian Republic, under pressure from the Entente, tore up the peace treaty and returned to the war.

The Kaiser was finally removed from de facto power in Germany. The military took complete control of the state. The Kaiserschlacht was more than successful—the Second Reich troops managed to reach Paris again.

During the Battle of Piave, Austro-German forces managed to break through the Italian defenses. Austria-Hungary's morale soared, especially thanks to a series of reforms implemented by Charles I.

The Zimmermann telegram was not intercepted by England. Mexico entered the war on the side of the Central Powers.

China also supported Germany by opening a second front with Russia in the Far East.

The meat grinder continued.

The chemical weapons race was gaining momentum. Lewisite was first used near Rouen in 1919. Sarin had been discovered much earlier.