During his leadership in June 1999, following the withdrawal of Serbian troops from Kosovo, NATO forces encountered a sudden hurdle when Russian troops seized control of an airfield near Pristina. In response, American General Wesley K. Clark, NATO's supreme commander, ordered Jackson to deploy tanks and soldiers to block further Russian landings. Jackson’s stark refusal, stating, “It’s not worth starting World War III,” highlighted the complexities of military command and international relations at the time. This moment of insubordination became a defining aspect of Jackson's reputation, earning him the nickname “Macho Jacko” in British media and earning respect from his peers for prioritizing peace over military orders.

The resolution to this standoff ultimately favored Jackson, as senior military leadership sided with his assessment of the situation. This incident stands as a significant example of the delicate balance between military strategy and diplomatic responsibility that leaders like Jackson often navigate in high-tension environments during military operations. Jackson's legacy reflects the complexities of military leadership and its implications on global relations.