Complex sentence: In December 2008 the Czech Air Force wanted to train in desert conditions for the upcoming mission in Afghanistan, and Israel offered their desert areas for this purpose, to thank the Czechs for training Israeli pilots when the country was first established.
Split into simpler sentences: In December 2008 the Czech Air Force wanted to train in desert conditions for the upcoming mission in Afghanistan. Israel saw it as an opportunity to thank the Czechs for training Israeli pilots when the country was first established.