The Czech Republic
A part of Eastern Europe, the Czech Republic is a landlocked country surrounded by four countries, including Poland and Germany, which made its participation key in World War II. Since then, it has fought numerous other battles, including the Israeli War of Independence and the Gulf War, while it continues to fight the Mali War.
With about 27K people in their army, they are not as powerful as numerous other states. However, good international relations always have them on the winning side. Most of its wars are fought as a member of the United Nations and Organization for Security and Co-operation in Europe.