The Secure World Foundation (SWF) is a private operating foundation that promotes cooperative solutions for space sustainability and the peaceful uses of outer space. In its statement, the SWF points out the irresponsible nature of the Russian ASAT test. The destruction of the Russian satellite resulted in the creation of at least 1500 pieces of trackable space debris, thus severely increasing the likelihood of additional collisions leading to even more pieces of space debris polluting the low Earth orbit. This orbital debris not only poses a threat to satellites operating in low Earth orbit, but also endangers human lives at the International Space Station and Tiangong space station.

The full statement of the SWF can be found here. 

While there might be no legally binding norms outright prohibiting the testing of anti-satellite weapons in outer space, conducting ASAT tests can still have legal consequences. Each ASAT test inevitably creates large amounts of space debris. This deliberate creation of space debris clearly contravenes well-established international guidelines and codes of conduct, such as the UNCOPUOS Space Debris Mitigation Guidelines. If any pieces of this debris cause a collision in outer space, resulting in loss of life or damage to property, the state that conducted the ASAT test can be held liable for all damage caused thereby.