incident in 1999, another proposal was raised to switched the air-independent propulsion of Agosta submarine to substitute with nuclear propulsion, however the proposal was dismissed. War on Terror in Afghanistan and operations in North-West (2001–present) After the 9/11 terrorist attacks in the United States, the sanctions on Pakistan were eventually uplifted, allowing the Navy to procure the U.S.-built weapon systems and warships to regain its ability to operate in the Indian Ocean as it became involved in war preparations during the standoff with India in 2001–02. In 2001, the Navy took serious consideration of deploying the nuclear weapons on its submarines although none of the nuclear weapons were ever deployed in the submarines. In 2003–04, there were several proposals made for acquiring the vintage aircraft carriers but the Navy itself had dismissed the idea since the country has not aspired to have an aircraft capability. In 2002–03, the Pakistan Navy deployment took place in the Indian Ocean, participating in the naval drills to combat terrorism from seaborne platforms, and eventually entered in defence negotiations with China for acquiring the technology to designing and building the guided missile frigates— the F-22P guided missile frigates were eventually built it in 2006–15. Since 2004, the Navy's deployment took place in Indian Ocean, playing a crucial role in the multinational NAVCENT in Bahrain, and took the leadership of the CTF-150 and CTF-151 as well as taking active participation in the Operation Enduring Freedom in 2006–10. In 2008, the task force group consisting of , , , and the Pakistan Air Force's Explosive Ordnance Disposal participated in the Exercise Inspired Union with the U.S. Navy in the Indian Ocean to develop skills in a prevention of seaborne terrorism. Its deployment in the War on terror also included their actions in the War in Afghanistan when the Navy's special forces were deployed to take participation in the Operations: Black Thunderstorm, Rah-i-Nijat, Mehran, and the Help. Despite its seaborne mission, the Navy had played an active role in controlling the insurgency in former tribal belt in Western Pakistan, mostly taking roles in managing logistics and intelligence gathering as well as conducting ground operations with the army in Western areas to track down the al-Qaeda operatives. From 2010 to 2011, the Navy was in a brief direct conflict with the violent TTP group and al-Qaeda, and its Naval Intelligence was able to track down the infiltrated militants within