Red lines in the Russo-Ukrainian War

It is a veiled threat of engagement intended to warn an opponent or observer not to interfere or undertake an action or behavior that would "cross the red line".

On 21 April 2021, Russian President Vladimir Putin made a speech in which he repeatedly warned the West of red lines that Russia would not accept.

Such actions may include the imposition of sanctions, the freezing of Russian or affiliated nation funds, and the donation of military goods to its perceived adversaries or others.

While the Russian Federation commonly uses the "red line" phrase in international politics, it has simultaneously used it to shape narratives aimed at domestic audiences.

[11] Some of the red-line threats from Russia may be bluffs solely to slow the supply of resources to Ukraine, making the West consider their options and delaying action.

Red lines set by Russia have affected NATO member-state decisions concerning Ukraine.

For example, the United Kingdom—apart from refusing to have British soldiers participate—has supplied most pieces of equipment and undertaken training missions that they are in a position to do; however, many other countries have shown timidity and concern over the red lines, resulting in a lack of, or delay in, providing assistance to Ukraine.

[76] Certain chemical weapons being deployed by Russia are pushing the boundaries of Western red lines, as is the treatment of civilians, especially Ukrainian children.