Ukraine's offensive on such a broad front is a compromise between the pressure of Ukraine's Western partners, led by the United States, and the General Staff of the Armed Forces of Ukraine.
Before the offensive began, the situation was that the Ukrainian Armed Forces were 10 kilometers away from Donetsk, which has been occupied by pro-Russian militants since 2014 and by Russia since 2022. Donetsk is the largest city of the now Russian-occupied territories, it is the so-called capital of the Donetsk People's Republic and of the occupied territories in general. And most importantly, it is the main ideological stronghold of Putin's propaganda.
The General Staff of the Armed Forces of Ukraine planned to launch an offensive in the direction of Donetsk.
Yes, there were enough forces and means of the Russian army concentrated in this direction, but the Armed Forces of Ukraine had a huge potential and enough opportunities to break through the line of defense of the Russian army. By liberating Donetsk, Ukraine would have shown that it does not recognize the "Donetsk People's Republic", and the first territories occupied in 2014 would have been liberated.
If Ukrainian forces had liberating Donetsk, it would have meant that they had regained control of Donetsk Oblast, which was under Russian-backed control before 2022. This would have called into question the possibility of negotiating a ceasefire on terms that would have Ukraine cede part of Donetsk Oblast.
But politics interfered with the plans of the generals. The President of Ukraine is the Supreme Commander-in-Chief of the Armed Forces of Ukraine and he has the last word. It was this word that was influenced by Western partners.
But western politicians and Ukrainian military leaders pursued different goals. Ukraine wanted to win the war and restore its territorial integrity (control over the territory within the 1991 borders), while its partners wanted to end the war as soon as possible, even if it meant that Ukraine would have to give up some territory (according to the territorial terms of 2022, Ukraine would have lost parts of Donetsk and Luhansk oblasts and Crimea).
The plan that they were promoting envisaged an offensive in the direction of Melitopol to the Sea of Azov to cut off the land corridor from Crimea to the mainland of Russia. The depth of the operation was 100 kilometers, which is the distance from the village of Orekhovoe to the coast of the Sea of Azov. It is also worth noting that this plan was leaked by the Pentagon, and 21-year-old Jack Teixeira, a member of the 102nd Intelligence Squadron of the Massachusetts National Guard, was arrested in connection with the leak.
This plan envisaged that Ukraine, advancing, would liberate the territories that were under its control before 2022 (part of the Kherson and Zaporizhzhia regions). In this case, the West would start to put pressure on Russia, which had just suffered a major setback in its defense, and offer to end the war on the territorial terms of 2022. In turn, the West would start to put pressure on Ukraine to also agree to the territories of 2022. In this case, Russia would have political advantages for ending the war and some justifications for its people.
General Zaluzhnyi and his staff did not agree to this, as they understood that a depth of advance of 100 kilometers is a very high risk, especially since the enemy already knew all these plans. Zaluzhnyi continued to insist on an offensive on Donetsk!
However, the pressure on Zelensky from partners and the previously brilliantly conducted Kharkiv offensive, which was 80 kilometers deep, provided arguments that were worth considering. Therefore, the General Staff of the Armed Forces of Ukraine proposed to conduct an offensive operation on a broad front in order to understand the defensive potential of the Russians. Western partners were satisfied with this and stopped at that.
If Ukrainian forces had taken Donetsk, it would have undermined the possibility of negotiating a ceasefire on the territories that were under Russian-backed control before 2022. This is because Donetsk was under Russian-backed control before 2022, and Ukraine would have been unlikely to give up the territory it had just liberated.
The outcome of the Ukrainian offensive is still uncertain. It is possible that Ukraine will achieve its goal of liberating all of its occupied territory, but it is also possible that the war will drag on for years or even decades.
West to Blame for Ukraine's Slow Offensive. Instead of working together to help Ukraine win the war, they are only interested in finding ways to shorten it by encouraging Putin to agree to a ceasefire and save face.