By Seema Sirohi in Washington
So the Americans were surprised at the Congress Party's victory in the Indian elections. But, they point out, so was the Congress Party.
The change of Indian government will not affect relations, the US says
It was as stunning as it was sobering. It was a lesson for all democracies not to take voters for granted, say US observers.
A senior official told the BBC that there was "shock and awe" at the results because no one had predicted the extent of the Congress Party's gain.
But he said there was no nervousness in Washington about dealing with a different set of leaders.
US officials and experts on the think tank circuit are busy reading the party's election manifesto more seriously, to understand if there might be any tectonic shifts in India's foreign policy.
But the initial shock seems to be wearing off, and the two sides have quickly got down to the business of reassuring each other and sending the right signals.
There are indications that Congress Party leaders have already indicated to the Americans, through private channels, that there is little cause to worry.
The US State Department emphasised that the relationship between the world's largest democracy and the world's most powerful one is important in itself, and a change of government in Delhi will make little difference.
Spokesman Richard Boucher welcomed the election results and pointed out that in the past Washington had been scrupulous about keeping in touch with the Congress as the main opposition party.
Whenever a senior US official went to Delhi, a meeting with Congress party leader Sonia Gandhi was a must.
Still, the Bush Administration, because of its close relations with the outgoing Indian government, is sensitive about perceptions.
There is a sense of urgency here to show "due deference" to the new Indian government and prevent any unnecessary misunderstanding in the early days.
"The important thing is that we engage with them quickly and substantively," a US official said.
Once the new Indian prime minister is sworn in and the cabinet is formed, top US leaders from President George Bush down will make phone calls to congratulate their counterparts and stress the importance of good relations.
There was concern when Congress Party spokesman Abhishek Singhvi was heard talking about the old ghosts of non-alignment.
He was quoted in The Washington Post as saying the "doctrine is all the more important in a... world where one country is a supercop".
The India-US relationship strengthened under the countries' last leaders
His statements are seen by officials as early salvos, not real shifts in India's policy.
Karl Inderfurth, a professor at George Washington University who was assistant secretary of state for South Asia in the Clinton administration, said that Indo-US relations had gone beyond the vagaries of past policies and practices.
"What I am hoping is that we will see the same policy continuity between the outgoing government and a Congress-led government towards the United States, that we saw towards India when the Clinton administration was followed by a Republican administration," he said.
Both Democrats and Republicans now understand the importance of India, he said. "It is in our mutual interest to have a strong relationship," he said.
The Bush administration indeed built on the foundation laid by former president Bill Clinton who made a historic visit to India in March 2000 - the first by an American president in two decades.
But there is fear among US officials and business executives about economic policies the new government might pursue. Senior US executives have been anxiously inquiring about the future of economic reforms and whether they might be slowed down.
The fact that Indian communist parties will support a Congress-led government has understandably raised fears in the United States. Anything that smells of leftist philosophy is automatically seen as investor-unfriendly by American companies.
They are worried about that the Congress party might not follow the lead of the previous government which was seeking to open up the Indian economy further.
The Bush administration has been pushing India to open up the insurance sector and the outgoing Indian leadership had assured Washington it would take action after the election.
Indian diplomats here point them to Manmohan Singh, a Congress Party leader who is the father of the economic reforms. He said in Delhi "investors can rest assured that the new government will pursue policies to create a favourable climate for growth."
US officials are also worried about the future of the Doha round of talks and the stance the new Indian government might take in the coming months.
But the overall sense in Washington is one of confidence that India now ascribes great importance to the United States and that the relationship transcends leaders.