Under Sharon, Israel continued to build upon the unprecedented coordination between the Israel Defense Forces and the South African Defence Force, with Israeli and South African generals giving each other unfettered access to each other's battlefields and military tactics, and Israel sharing with South Africa highly classified information about its missions, such as Operation Opera, which had previously only been reserved for the United States. In 1981, after visiting South African forces fighting in Namibia for 10 days, Sharon argued that South Africa needed more weapons to fight Soviet infiltration in the region. Sharon promised that the relationship between Israel and South Africa would continue to deepen as they work to "ensure the National Defense of both our countries". The collaboration in carrying out joint-nuclear tests, in planning counter-insurgency strategies in Namibia and in designing security fences helped to make Israel, South Africa's closest ally in this period.