In a year of renewed interest in the OSCE, the 20th edition of the OSCE Yearbook contains analyses, descriptions and reports by experts, insiders and decision-makers on the world's largest regional security organization, its work and participating States. A special focus section considers the Helsinki +40 Process against the background of the crisis in Ukraine. Highlights include former Russian Foreign Minister Igor Ivanov on the OSCE's ongoing relevance, and OSCE Secretary General Lamberto Zannier on the Organization as a regional arrangement under the UN Charter. Steven Pifer also discusses recent events in US-Russia relations. The participating States in the spotlight this year are Turkmenistan, newcomer Mongolia, and the UK, in the context of the referendum on Scottish independence. The section on conflict prevention and dispute settlement is largely dedicated to the Ukraine crisis. Here, renowned experts deal with the challenges and opportunities presented by the OSCE's Special Monitoring Mission; analyse the strategic struggle between Russia and Ukraine; consider Russia's motivations; and outline the development of Ukrainian civil society. Other contributions are dedicated to the Nagorno-Karabakh conflict, election observation, conventional arms control against the backdrop of the Ukraine crisis, and the OSCE Mediterranean Partnership four years after the "Arab Spring".