NEW DELHI: Pakistan’s use of F-16s against India on February 27 has raised tough questions for Washington, which had justified the sale on grounds of not just combatting terror but also as providing “deterrence value” to Pakistan in case of a future conflict with India.This is exactly how the then US Ambassador to Pakistan Anne Patterson had framed her embassy’s pitch for an exception to allow for diversion of American counter-terrorism financial assistance to Pakistan for purchasing F-16s and related enhancements.The package included 500 AIM-120-C5 Advanced Medium Range Air-to-Air Missiles (AMRAAMs), remnants of one of which was recovered and exhibited as evidence by the Indian Air Force “An enhanced F-16 program also has deterrence value by giving Pakistan time and space to employ a conventional, rather than nuclear, reaction in the event of a future conflict with India,” wrote Patterson in her 20-paragraph communique, as disclosed by WikiLeaks , to Washington on April 24, 2008, giving reasons to justify the deal using US taxpayer money.Those familiar with the ongoing conversation with the US told ET that India has already asked the Donald Trump administration to ascertain if the use of F-16s and AMRAAMs violated enduser conditions.And if not, then New Delhi would want to know from Washington when it intends to revisit the terms. On Tuesday, the IAF put out a detailed statement on what happened on February 27, which appeared to be almost a replay of the scenario which Patterson had painted.“During combat, use of F-16 by PAF and multiple launches of AMRAAM were conclusively observed. Prompt and correct tactical action by Su-30 aircraft, in response to AMRAAM launch, defeated the missile. Parts of the missile fell in an area east of Rajouri in J&K, injuring a civilian on ground,” the IAF said in the statement.Back in 2008, Washington moved for Congressional approval to divert funds, essentially a subsidy, within five months of Patterson’s cable. And in his testimony on September 16, 2008, before the House Committee on Foreign Affairs, admiral Jeffrey Wieringa, then director of the US Defence Security Cooperation Agency, disclosed that the Pakistan programme was structured by three Letters of Acceptance (LOAs) — first for 18 new F-16s, second for specialised munitions like the AMRAAMs, and third for mid-life update of Pakistan’s older fleet of 46 F-16s.In the context of the use of AMRAAMs by Pakistan, admiral Wieringa’s statement seems instructive. “The second LOA provides for munitions and includes: 500 AIM-120C-5 AMRAAM, 750 Mark 84 2,000 lb general purpose bombs, 700 BLU-109 penetrator bombs…these weapons will be available to Pakistan beginning June 2010.”India was, however, assured by the George W Bush administration that the US had ensured a stringent monitoring system on the use and deployment of F-16s. This included informing the US on deployment of these assets in an exercise or in an operation in a third country.On July 20, 2006, around the time when the decision to resume F-16 sales to Pakistan was made, the then assistant secretary of state for military affairs John Hillen informed the same House Committee of the stringent conditions.“There is a two-man rule, so to speak, for access to this equipment and restricted areas, and F-16 flights outside of Pakistan or participation in exercises and operations with third nations must be approved by the United States government,” he said.The incidents of February 27 have, however, brought the whole issue back to the fore. In 2016, India had successfully blocked the effort of the Obama administration to sell eight additional F-16s to Pakistan by lobbying aggressively in the Congress.