Grom (Thunder) is a portable air defense weapon, it is a Polish version of the Soviet Igla. Since the 1970s, Soviet Poland had licensed Strela-2M missiles, which were known locally as Strzala-2M, and by the late 1980s Poland had obtained a production license for the more modern Igla missile.
But in 1991 the Soviet Union collapsed and the Warsaw Pact was dissolved before Poland obtained a production license for Igla.
This left Poland without a modern air defense missile. And in 1992, local military research and development offices began work on a new design similar to the Igla.
Polish intelligence also obtained blueprints for the Igla missile from the works of LOMO in Leningrad (now Saint Petersburg).
This helped develop the new missile, known as the Grom. Poland has already all the capabilities to produce this missile.