Bangladesh, April 12 -- Back in late October 2017, Russia donated six MiG-29 fighter jets to Serbia. Less than a year and a half later, Belarus did the same, donating four aircraft of the same type. This was a major boost for Belgrade, as it previously had only four (three of which were airworthy) MiG-29 fighter jets that survived NATO aggression in 1999. Moscows and Minsks military aid was instrumental in preserving the Serbian Air Force and Air Defense (RViPVO), as it brought the number of operational fighter jets to 14, an increase of 250%. Serbia paid for and conducted the modernization, bringing all jets to the MiG-29SM+ standard. The cost of the upgrade was reportedly less than $400 million altogether, an excellent deal given the ci...