Which country ratified the Kyoto Protocol in late 2004 and thus caused it to become an international law?

The country that ratified the Kyoto Protocol in late 2004, thereby causing it to become international law, was Russia. Russia’s ratification was crucial because it pushed the total emissions of the countries that ratified the Protocol past the required threshold for it to enter into force. The Kyoto Protocol officially entered into force on February 16, 2005, ninety days after Russia’s ratification. This marked a significant milestone in international efforts to combat climate change through legally binding commitments to reduce greenhouse gas emissions.