Supplying Arms to Ukraine Is Not an Act of War

People all over the world are watching the media coverage of Russia’s attack on Ukraine. Most of those are watching in horror, disgust, and anger over the senseless loss of life, liberty, and property. Many citizens want their countries to support Ukraine but also fear being drawn into war.
Even though the citizens want to help Ukraine, they are concerned whether their country’s support of Ukraine could be considered by Russia an act of war. The leaders of many countries are trying to walk the fine line of helping Ukraine without being pulled into a military conflict with Russia.
While we want our leaders to be cautious and make wise decisions for our countries, we also want them to be strong and defend democracy. World leaders should not fear supporting Ukraine.
Read on to understand why supplying arms to Ukraine is not an act of war.
The Law of Neutrality
The law of neutrality has been recognized for centuries; however, its meaning has undergone a radical transformation in the last century. From its origin, this law meant that a country could declare itself neutral, and no warring country also called a “belligerent,” could make the neutral country enter the conflict.
A neutral country had the right to trade and conduct business with a warring government without the other warring country taking action against it. However, a neutral country was required to be completely impartial in its dealings with the warring nations.
Even in the early 20th century, the law of neutrality required a neutral country to deal with both warring countries on equal footing. Sanctions to one warring country must be applied to the other warring country in like measure.
But, in 1928, the Kellogg-Briand Pact, which was adopted by more countries than any other war treaty in history, made war a crime. This pact helped to develop the United Nation’s recognition of a country’s right to self-defense.
It has been interpreted by some of our best legal minds that the Kellogg-Briand Pact’s outlaw of war confers the right to a neutral country to discriminate against war aggressors. As former United States Attorney General Jackson explained the Kellogg-Briand Pact, “No longer can it be argued that the civilized world must behave with rigid impartiality toward both an aggressor…and the victims of unprovoked attack….such an interpretation of international law is not only proper but necessary if it is not to be a boon to the lawless and the aggressive.”
This interpretation of international law has been accepted for nearly a century now. It is common for neutral countries to discriminate against aggressors by use of sanctions and by providing support and weapons to their opponents, without those actions being labeled acts of war. Thus, if the US sends weapons to Ukraine, there is no violation of the law of neutrality.
Co-Belligerency
Co-belligerency generally refers to the relationship between ally nations engaged in a common armed conflict. There are instances when the relationship of co-belligerents is apparent such as the United States and the United Kingdom in World War II. However, the connection is not always so obvious.
Some have asked whether sending support, notably weapons, to Ukraine makes a country a co-belligerent with Ukraine. Many people wonder exactly what constitutes an act of war.
Under Article 51 of the United Nations Charter, it is lawful and justifiable for a neutral country to provide support to a country engaged in self-defense. Moreover, most of the world agrees that Ukraine is involved in the act of self-defense against unprovoked attacks from Russia.
The following acts of support to Ukraine do not make a country co-belligerent:
- Sanctions against Russia;
- Sending financial support to Ukraine;
- Sending humanitarian aid to Ukraine;
- Helping refugees fleeing Ukraine; and
- Sending weapons and ammunition to Ukraine.

Based upon the interpretation of international law and the concept of co-belligerency, it seems clear that providing support of all types, including supplying weapons, to any country trying to defend itself against hostile attack is not to become a co-belligerent. Therefore, supplying arms to Ukraine does not make a country a co-belligerent.
Use of Force
Another question to consider is whether countries are engaging in the use of force by supplying weapons to Ukraine under the United Nations Charter Article 2(4). If providing weapons to Ukraine and issuing sanctions against Russia were considered a use of force, it would open the aiding country to countermeasures from Russia. The question of whether a government has engaged in a use of force is a separate issue from whether it has acted as a co-belligerent or acted against the law of neutrality.

Russia's invasion of Ukraine does not seem to be reaching a resolution anytime soon. Even though talks are being held about neutrality...
However, because Article 51 of the United Nations Charter and the international law customary interpretation finds assistance to a country engaged in self-defense is lawful, it can not be classified as a use of force. The use of force necessitates an act of aggression. However, supplying weapons to another country for the purposes of self-defense can hardly be an act of aggression.
When countries issue sanctions against Russia, they tell Russia that they disapprove of their actions. Why should there be any surprise that a government issuing sanctions against Russia for unprovoked attacks would then provide weapons to the attached country to defend itself? If Ukraine is permitted to engage in self-defense, then why would a country aiding Ukraine in their act of self-defense be at fault?
Weapons Tracing Implicates Ukraine Conflict
An important aspect of the attacks on Ukraine is the fact that not only is Russia attacking Ukraine from outside, but also from within. Studies such as the one reported by The New York Times show that Russia has been systematically supplying weapons and ammunition to pro-Russia supporters within Ukraine.
Research on the weapons recovered from these separatist groups can be traced by serial numbers to the manufacturers of the weapons and show that they could have come from no other source than Russia’s military. There is evidence that the separatist groups in Ukraine are receiving direct support from Russia.
Russia’s military has supplied all types of weapons to militant groups in Ukraine, including the following:
- Granade launchers;
- Sniper rifles;
- Land mines;
- Anti-handling devices, also known as booby-traps;
- Shoulder-fired antiaircraft missiles; and
- Thousands of rounds of ammunition.
What This Means for Ukraine
All countries that believe Ukraine has been wrongfully attacked should take whatever actions they can to provide support to Ukraine. Sanctions against Russia are a strong act of support of Ukraine. Providing safe refuge to the citizens of Ukraine is monumental support of Ukraine and sends a strong message to Russia. Sending financial aid to agencies that provide support to Ukraine is also a decisive act of support for Ukraine and against the aggression of Russia.
However, one of the most potent acts of support a country can take is to provide weapons to Ukraine. Ukraine should be able to defend itself against the unprovoked attacks of Russia, and civilized nations should aid Ukraine in their efforts of self-defense.
Most civilized nations want to see an end to Russia’s attacks on Ukraine. Most agree that Ukraine should defend itself against these unprovoked attacks.
Conclusions
Thankfully, there is no reason why any country should not support Ukraine. Providing help to Ukraine is not against any rules of war. Providing weapons to Ukraine does not violate the law of neutrality, does not make a country a co-belligerent, and is not a use of force. Providing weapons to Ukraine is not an act of war.
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