Less than 25 years after American and NATO intervention ended a brutal war in the Balkans, one party to the conflict is swaggering and boasting over its new military hardware. Serbia on Saturday publicly displayed a Chinese anti-aircraft missile system, according to The Associated Press. Serbian President Aleksandar Vucic said the missiles give Serbia a “powerful deterrent” against all threats. “We will no longer allow [ourselves] to be a punching bag for anyone,” Vucic said after the display, according to the AP. The wire service interpreted that comment as a reference to the 1999 bombardment of Serbia in 199 after...