By Antonio BronicKARLOVAC, Croatia March 6 (Reuters) - Croatia is set to resume mandatory military service for the first time in 17 years as part of the European Union member's broader strategy to address security concerns in Europe and the Western Balkans.On Monday, 800 recruits will start two-month basic training in military compounds across the country.Croatia amended its defence law last October to introduce mandatory service in line with European trends and as tensions with Russia spurred c...