Complex sentence: The present dispute began shortly after the 1960 passage of United Nations General Assembly Resolution 1514 on decolonization, when Argentina reasserted its sovereignty claims to the UN special committee for non-self-governing territories.
Split into simpler sentences: The present dispute began shortly after the 1960 passage of the United Nations General Assembly Resolution 1514 on decolonization. Argentina then reasserted its sovereignty claims to the UN special committee for non-self-governing territories.