Blackwill's term saw heightened activity on the Indo-Pak front especially after the September 11 terror strikes and the military actions in Afghanistan and Iraq leading to a number of US leaders to visit New Delhi.

Referring to his stint, Blackwill said he would in particular like to thank senior members of the Indian government for their 'unfailing generosity' in helping him carry out his official duties.

"I especially have in mind Prime Minister (Atal Bihari) Vajpayee, Deputy Prime Minister Lal K Advani, Finance Minister Jaswant Singh, External Affairs Minister Yashwant Sinha, Defence Minister George Fernandes and Principal Secretary and National Security Adviser Brajesh Mishra."

"I would also like to express my appreciation to the Leader of the Opposition Sonia Gandhi for her many courtesies to me," he said.

Blackwill said in naming him as the envoy to this 'magnificent country', President Bush had done him a great honour.

"I have tried to justify his confidence by energetically promoting his vision of India as a rising great power of the 21st century, and his primary goal of the world's oldest and largest democracies operating together to transform their relations, to forge a concentrated strategic collaboration for the decades ahead," he said.

He said under the leadership of Bush and Vajpayee, Washington and New Delhi have made enormous strides to achieve this aim.

Before transformation of the US-India relationship began, it was rare for members of a president's cabinet and senior American officials to visit India.

"Almost a hundred have come in the past two years," he pointed out.

Two years back, there were US economic sanctions against India related to its 1998 nuclear tests. "Today, these sanctions are long gone."

Unlike two years back, when the militaries of the two countries conducted no joint operations, "today they have completed six major training exercises, and our defence cooperation flourishes."

Observing that the 'troubled past is behind us', he  expressed confidence that 'close and cooperative relations between the US and India will thrive in the decades ahead and most crucially because of the convergence of common democratic values and vital national interests'.

Blackwill said the two countries had 'overlapping vital national interests' in promoting peace and freedom in Asia, slowing the spread of weapons of mass destruction, and combating international terrorism.

"As I have said many times during my stay in India, the fight against international terrorism will not be won until terrorism against India ends permanently. There can be no other legitimate stance by the US, no American compromise whatever on this elemental geopolitical and moral truth."

He went on to add that the US, India and all civilized nations must have zero tolerance for terrorism.