German Democratic Republic, or East Germany, influenced by the Soviet Union. The GDR had much of its industrial infrastructure removed during the Cold War, and for many years unified Germany struggled to build infrastructure in the former East Germany up to the level of former West Germany. Peace did not come to Yugoslavia for a decade, and by 2003, there were still many NATO and EU peacekeeping troops present in Bosnia and Herzegovina, North Macedonia, and Kosovo. War severely hampered economic growth, with only Slovenia making any real progress in the 1990s. The European economy was affected by the September 11 Attacks in the United States in 2001, with Germany, Switzerland, France, and the United Kingdom being the worst hit. But, in 2002/2003, the economy began to recover from the attacks in US. The economy of Europe was by this time dominated by the EU, a huge economic and political organization with then 15 of Europe's states as full members. EU membership was seen as something to aspire to, and the EU gave significant support and aid to those Central and Eastern European states willing to work towards achieving economies that met the entry criteria. During this time, 12 of the 15 members of the EU became part of the Eurozone, a currency union launched in 1999, whereby each member uses a shared currency, the euro, which replaced their former national currencies. Three states chose to remain outside the Eurozone and continue with their own currencies, namely Denmark, Sweden and the United Kingdom. 2004–2007: EU expansion In early 2004, 10 mostly former communist states joined the EU in its biggest ever expansion, enlarging the union to 25 members, with another eight making associated trade agreements. The acceding countries are bound to join the Eurozone and adopt the common currency euro in the future. The process includes the European Exchange Rate Mechanism, of which some of these countries are already part. Most European economies are in very good shape, and the continental economy reflects this. Conflict and unrest in some of the former Yugoslavia states and in the Caucasus states are hampering economic growth in those states, however. In response to the massive EU growth, in 2005 the Russian-dominated Commonwealth of Independent States (CIS) created a rival trade bloc to the EU, open to any previous USSR state, (including both the European and Asian states). 12 of the 15 signed up,