The Commander-in-Chief of the Armed Forces of Ukraine Oleksandr Syrskyi began planning the operation in the Kursk region in July, when he was under pressure due to the active Russian offensive in Donbas.
The Economist writes about this with reference to sources.
The general considered several scenarios of the Ukrainian armyʼs attack on the weakest points of the Russian defense: an invasion of Bryansk or Kursk region or both. The goal was to reduce the offensive of Russian troops in the Donbass and gain a trump card for any future negotiations.
Syrskyi kept his plans a secret. He shared them only with a few generals and security forces. He also communicated with President Volodymyr Zelensky face to face, without his staff. A significant part of the intelligence was carried out by army intelligence, not by the Main Directorate of Intelligence (known as GUR) of the Ministry of Defense. They were included in the operation at a late stage.
Western allies were also left in the dark. According to the sources, two operations planned by Syrskyi failed because of the West. In one case, the information got to the Russians, and in the other, the Western allies ordered not to implement the plan. Secrecy allowed the Ukrainian army to launch an attack before the Russians realized what was happening.
"They realized something was going on, but probably assumed we would need American approval for such a bold operation," one of the sources said.
Oleksandr Syrskyi also misled Russia by concealing the arrival of the most prepared units to the border of the Sumy region under the pretext of defense against an alleged Russian attack on the region.
At the beginning of August, the Ukrainian military began to suspect that something significant was happening when they were issued new helmets with integrated headphones and new assault rifles.
The Commander-in-Chief now concentrated on expanding his flanks along the border. The Ukrainian contingent establishes control over the southern bank of the Seim River northwest of Sudzha. Russia initially considered the breakthrough not too serious. However, it is now raising more prepared troops to respond to the invasion.
The Kursk operation
For the first time, it became known about the offensive of the Defense Forces in the Kursk region of the Russian Federation on August 6 — then Russian telegram channels and "military corps" wrote about it.
Until August 12, Ukraine did not officially confirm the operation in the region, until the Commander-in-Chief of the Ukrainian Armed Forces Oleksandr Syrskyi informed that Ukraine controls almost 1 000 km² of the Kursk region of Russia. The exact number of captured Russians is unknown, but high-ranking Ukrainian officials (Syrskyi in particular) stated that hundreds of Russian soldiers were captured on certain days of the operation.
For self-defense, the Ukrainian military formed a buffer zone on the territory of the Kursk region. Ukraine plans to open humanitarian corridors there for the evacuation of civilians, admit representatives of the UN and the Red Cross, and arrange the supply of food and medicine.
On August 15, Ukraine created the first military command post in the Kursk region.