Martin is a Distinguished Fellow at GLOBSEC, focusing on security and defence policy issues. In 2023, Martin served as Minister of Defence of the Slovak Republic, as part of a technocratic government.
Previously, Martin served as Director General for Defence Policy at the Ministry of Defence of the Slovak Republic. He was responsible for developing and implementing defence policy, defence planning and international cooperation. Between 2011 and 2020 he worked at the at the Ministry of Foreign and European Affairs of the Slovak Republic as the Security Policy Director and was posted to the Embassy of the Slovak Republic in Washington, DC. He transferred to the MFEA in 2011 from the Slovak Ministry of Defence, where he held various positions, including Director for International Relations. The Ministry of Defence posted Martin to Brussels to be its representative in working bodies of the EU Council from 2006 to 2009. In 2010 he deployed to Pristina, Kosovo as a UN Volunteer.