What is the main cause of failure of Pak-Iran-India gas pipeline project?

THE fundamental reason for the collapse of the Pak-Iran-India IPI gas project, which forced India to withdraw in 2009 and left the Pakistan-Iran leg unrealized, was the result of US pressure on economic and political levels. It was claimed by India on the basis of security concerns, whereas the financial barriers by Pakistan did arise, yet the key resistance was the US sanctions threat on Iran. That threatened US sanctions spooked investors, financiers, and partner countries from concluding a deal that would invite US sanctions.