Over the past two decades, Poland significantly strengthened its ties with the United States, thus becoming one of its closest allies in Europe. Poland was part of the US-led coalition force during the Iraq War in 2003, and sent its troops in the first phase of the conflict, jointly with the United Kingdom and Australia. Along with NATO, Poland maintains military presence in the Middle East, the Baltic states and in the Balkans. Historically, Poland has had particularly friendly relations with Hungary; this special relationship was recognized by the parliaments of both countries in 2007 with the joint declaration of March 23 as "The Day of Polish-Hungarian Friendship".