Red lines in the Russo-Ukrainian War

The term red lines has seen use in the Russian invasion of Ukraine in 2022, and is a veiled threat of engagement that is intended to warn an opponent or observer not to interfere or undertake in an action or behaviour 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. The warnings were repeated on many occasions up to the date of the Russian invasion of Ukraine on 24 February 2022.

To some experts, the number of red lines that have been crossed reveal the inability for belligerents involved in the war to project power internationally.

Russia's red lines
The mention of red lines have been in common use since the very start of the renewed conflict in Ukraine to justify the war. In February of 2022, President Vladimir Putin of the Russian Federation stated that the United States and its Western partners had crossed a red line with regard to Ukraine, which resulted in the consequence of Russia having to undertake its "Special Military Operation" against Ukraine due to the threat imposed from Ukraine to the very existence of the Russian Federation.

Crossing a red line to the Russian Federation is often identified as being an action that damages Russian national interests. 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 other.

While commonly used by the Russian Federation in international politics, Russia has simultaneously used the red line phrase in shaping narratives aimed at domestic audiences.

In June 2023 President Putin said that Russia would keep responding to breaches of its red lines. President Putin has been consistent with regard to the threat of nuclear action being used solely in the event of crossing the red line of an existential threat to the state.

In 2023 Russia made 15 official "red line" statements, compared to 24 in 2022.

Usage of red line warnings
Russia has used the phrase "red line" often, and because some of these lines have been crossed without major repercussions, some believe that Russia has devalued the impact of their threats, with the threats appearing more as bluffs.

There may be an actual red line that Russian and the Kremlin really have, but it is largely unclear what exactly it consists of.

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

Others may be used just to show an element of escalation has taken place once a line is crossed. Red lines are nearly always soft, variable and adjustable rather than hard-line positions that are immutable.

In diplomacy, both Russia and Ukraine have mentioned red lines when referring to acceptable peace terms. One such example of a diplomatic Russian red line leaves Russia keeping Crimea, and another Ukrainian red line sees all Russian forces leave territory that belonged to Ukraine on 31 December 1991. These red lines appear incompatible.

Tacit rules
As time has progressed in the war, a set of tacit rules has emerged which fit between current operations and red lines and affect the rule creator.

Examples of such tacit rules include: Under these stated rules, Russia would cross a red line if they attacked a NATO country, and NATO would cross a self-imposed red line if they sent troops into Ukraine. The above aim to limit an expansion of the war; however, it is not all one-sided, as other tacit rules are:
 * NATO will defend its territory.
 * No NATO forces will operate inside Ukraine against Russian forces.
 * NATO will not operate in the airspace over Ukraine, in order to avoid a direct confrontation.
 * US and NATO will share intelligence and satellite imagery with Ukraine.
 * NATO countries will provide weapons and ammunition to Ukraine.
 * Ukraine will not use NATO weapons to strike inside Russia's pre 2014 borders.

Tactics used to contravene red lines
Red lines come in differing levels of severity. Some of these are bluffs, with parties to the conflict having given many red lines that were transcended without issue during the last decade. To counter red line policies, a number of tactics have been employed by the belligerents and non-belligerents alike. Such counter-measures aim to allow the crossing of red lines with significantly fewer or no consequences.


 * Noise - The West has often employed a tactic of “noise” before a decision is seen to take place to cross a Russian red line. This noise is often employed in the form of having a public debate, frequently over a month or even longer involving numerous countries. Often times these debates involve the possibility of the first weapon being sent from, or via, a third country. Once this has occurred and a small number of arms have arrived already, the red line has effectively been diluted without a significant reaction. Because of the noise surrounding the discussions, no one event can be seen to be a significant or important enough event to be defined as the red line crossing moment.


 * Undermining the red line - Another tactic used is the supplying of something similar to a red line weapon, such as the supply of modern tanks. For example, when France agreed to supply a number of AMX-10 RC wheeled modern “tanks”. These wheeled tanks were not exactly what Ukraine wanted or needed, and as a result it caused very little reaction from the Russian Federation while also enabling the ability to further dilute the debate of whether it was wheeled vehicles or tracked vehicles which the Russian Federation objected to, rather than the fact it was a "modern western" tank. Following this, Challenger 2 tanks were then promised in addition to modern Leopard 2 and M1 Abrams tanks.


 * Similar, but not as good - With long range missiles, the Russian Federation objected to the United States of America supplying ATACMS with a range of 300 km, as the missiles could be used to attack targets in Russia. In response to this, the United Kingdom supplied its “Storm Shadow’’ cruise missiles with a range of 250 km. These weapons allowed Ukraine to strike into Russian-held territory in Eastern Ukraine, while also having enough range to hit valuable targets within the legal borders of the Russian Federation. This enables Ukraine to destroy command and logistics centres located in occupied Ukraine that had previously been moved back out of HIMARS range. The Russian Federation having a hard-line on the 300 km range found its red line diluted, and there was no tangible reaction.


 * Drip feed - A decision to supply a large quantity of modern tanks would likely provoke an immediate reaction from the Russian Federation, however when a decision is made for a country to supply a number as small as four tanks, another country may supply seven, and a third country another four. If aid is given in this manner, Russia seems unable to show that a red line has been crossed. By drip feeding from multiple countries, no one country attracts a significant adverse reaction from what is effectively directly crossing a red line.


 * Calling the Bluff - Belligerents have few options to retaliate in a meaningful way against other parties for a breach of a red-lines, without significantly widening the scope of the war, or resorting to a nuclear option.

Effect of red lines
Red lines set by Russia have had an effect. The United Kingdom, apart from refusing to have British soldiers participate, have 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.

Russia appears to generally abide by the Western red lines, although certain chemical weapons deployed are pushing the boundaries, as is the treatment of civilians, especially Ukrainian children.

Red lines of non-belligerent states
Many countries outside of the direct belligerents active in the Russo-Ukrainian war have interests within it. As a result, this has caused foreign parties such as the United Kingdom, the United States, and the People's Republic of China to establish their own so-called red lines.

When the international community refers to the crossing of "red lines" it tends to be limited to the use of nuclear, chemical or biological weapons and the supply of other lethal weapons. Below, a small list of such red lines has been provided.
 * The People's Republic of China was warned by the United States not to supply lethal weapons to Russia, or else it would face secondary sanctions.
 * South Korea was warned by Russia that supplying weapons would cross a red-line, whereby Russia would respond by supplying weapons to North Korea.
 * The European Council of the European Union implicitly drew a red line when the authorities of Georgia rejected a judicial reform and European Union loan package to reduce the influence of pro-Russia billionaires in the country, by offering EU membership candidate status to Ukraine and Moldova (but not Georgia) in June 2022.
 * Iran was warned that supplying missiles to Russia would cross a red-line resulting in secondary sanctions.
 * China has told Russia it would cross a red-line by using nuclear weapons in Ukraine, whereby China would stop implicitly supporting Russia in the war.