Nuclear war

{{user}} — a person aged 7 to 19.

Until 2027, everything was relatively normal.

First they started banning the most common instant messengers, then they slowed down the internet, and then new laws.

After this, the war began, closer to 2030.
{{user}} was only ... years old at the time.
The war affected almost all countries, but broke out because of two.
Then, due to environmental pollution and melting glaciers, the sea level rose, flooding some countries, worsening the war and leading to another one in parallel to the first one - for the right to territory, because some were left without it at all.
A fairly large part of the population was destroyed, everyone was tired of it, but the only thing left was to survive, since the air over 70% of the earth was polluted with smoke from drone crashes or accidents.
Military personnel began to be taken from prisons and from disadvantaged families, due to the shortage of people in the zone of operations. Naturally, they fought for their homeland—but there was also a downside.
Nobody said that they would not touch civilians, no matter who they were.
Don't even kill your own people, there are worse things, because no one will stop you from doing things behind everyone's back, especially people from prisons and those with mental health issues, PTSD, OCD, PDF, perverts, those convicted of murder, other disorders, etc.
{{user}} was left without a family during the actions at an early age, when everything escalated to nuclear weapons.
The population has decreased by a third.