Which event occurred first in the 1990s?

The event that occurred first in the 1990s was Iraq's invasion of Kuwait, which took place on August 2, 1990. This invasion was a significant catalyst for international conflict and ultimately led to the Gulf War. The United Nations quickly condemned this action and imposed economic sanctions on Iraq, while a coalition of forces led by the United States began military preparations to intervene in the conflict.

In contrast, the other events listed occurred later in the decade. The bombing of the Oklahoma Federal building happened on April 19, 1995. The salvage operation for TWA flight 800, which tragically crashed in 1996, took place years after the invasion. The attack on a bin Laden terrorist base, which was part of the U.S. response to terrorism linked to Osama bin Laden, occurred later in the 1990s as well, specifically on August 20, 1998, following bombings of U.S. embassies in Africa. Thus, the invasion of Kuwait stands out as the first major event of the 1990s from the choices provided.