I find usually a sentence that starts with "With all due respect" goes on to show no respect at all. It is not me saying that the invasion is illegal: it is everyone except Russian Propagandists who say so. Google "illegal invasion of Ukraine" and read any of the 14.6 million results. To quote a couple:

"Broadly speaking, the 2022 Russian invasion of Ukraine can be grasped as illegal precisely as it broke and undermined the UN Charter - arguably one of the most significant documents of international law."

“The use of force by one country against another is the repudiation of the principles that every country committed to uphold. This applies to the present military offensive. It is wrong. It is against the (United Nations) Charter. It is unacceptable. But it is not irreversible,” Guterres told reporters at U.N. headquarters in New York.

“Stop the military operation. Bring the troops back to Russia. We know the toll of war.”"

read more here: https://www.cfr.org/article/how-russias-invasion-ukraine-violates-international-law