understand the reciprocity

The US Embassy in New Delhi had been issued with 11 special diplomatic cards that entitled them to special privileges at the Indira Gandhi International Airport in New Delhi.
Four cards were permanent, including the ambassador and the deputy chief of the mission, while seven cards were transferable, to be used by US embassy staff.
These entitled them to receive special privileges such as parking, jumping the queue at immigration counters and access to VIP lounges. 

Persons working at the American School, American Centre, and a number of other places  have diplomatic identity cards as a courtesy. 

Indian consular staff have no such privileges in the US. This was a unilateral courtesy extended to US diplomats.

In the US, identity cards issued to diplomats and consular officers clearly specify the level of immunity the cardholder enjoys. In select cases, it clearly says no immunity from arrest.
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 US  deny Indian embassy in Washington, DC reserved parking space.

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Washington argues that she does not have immunity from arrest.
 Raymond Davis  was arrested for the murder of two Pakistanis in Lahore in 2011. The US State Department had said Raymond cannot be arrested as he was working with the American Consulate.
As it was later revealed, he was not even a consular employee but a contractor employed by the CIA! It is strange that Americans then argued that he had immunity while now asserting that the Indian Deputy Consul General does not have such immunity..

 

http://www.dailymail.co.uk/indiahome/indianews/article-2526691/We-want-US-know-mean-business-India-cancels-privileges-American-diplomats-airports-country.html

http://www.dailymail.co.uk/indiahome/indianews/article-2525468/Manhattan-Attorney-Preet-Bharara-scanner-targeting-Indians.html