The fate of the US military bases in the country was greatly affected by the end of the Cold War, aside from the catastrophic eruption of Mount Pinatubo in 1991 which engulfed the installations with ash and lava flows. The nearby Clark Air Base was eventually abandoned afterwards, while the Philippine Senate voted to reject a new treaty for Subic Naval Complex, its sister American installation in Zambales. This occurrence had effectively ended the century-old US military presence in the country, even as President Corazon Aquino tried to extend the lease agreement by calling a national referendum, leaving a security vacuum in the region and terminated the inflows of economic and military aid into the Philippines.