But before answering back to the US, what we really need to know is what exactly does the law say? Is Devyani really immune to prosecution and arrest?
Some part if it still remains under wraps. Certain issues like whether the Indian official is immune from prosecution, whether she was immune from arrest in the first place and what is the legality of India's response to the incident is not thought of.
The European Journal of International Law came up with these points and tried to decipher them.
Immunity from prosecution
According to article 43(1) of the Vienna Convention on Consular Relations (1963), which includes India and the US as parties, "Consular officers and consular employees shall not be amenable to the jurisdiction of the judicial or administrative authorities of the receiving State in respect of acts performed in the exercise of consular functions."
If simplified, it means that the consular officials are only entitled to immunity with respect to their official acts (immunity ratione materiae) and only with respect to those official acts carried out in the exercise of their consular functions.
This also means that the host state (the US) is entitled to prosecute consular officials for private acts. And employing domestic staff is definitely a private act since it is not one done in the exercise of consular functions. Therefore, Devyani is not immune from prosecution in the US with regard to the visa fraud charges.
Immunity from arrest
Even though Devyani was entitled to prosecution does not mean that she was entitled to arrest as well. In certain cases, immunity from arrest or detention is provided, even if the act is related to a private/non-consular act and even when the host state is entitled to commence criminal proceedings.
Article 41 provides that "Consular officers shall not be liable to arrest or detention pending trial, except in the case of a grave crime and pursuant to a decision by the competent judicial authority".
Devyani Khobragade is not immune to prosecution in the US
It means that even if the US was entitled to institute criminal proceedings against the Indian Consular office, a separate question needs to be asked as to whether the US was entitled to arrest and detain her, even if only briefly. The answer to this question depends on (i) whether the charges against her are ‘grave' and (ii) whether the decision to arrest was pursuant to a decision of a judicial authority.
With respect to (ii) it appears that Devyani was arrested on the basis of a judicially issued arrest warrant.
India's response legal?
Though most part of India's response was unfriendly, that was not unlawful and could be considered as act of retorsion.
But then, the most serious of India's acts is the removal of the barricades in front of the US embassy in Delhi. This act may potentially be in breach of India's obligation to protect diplomatic premises.
Article 22(2) of the Vienna Convention on Diplomatic Relations contains that "The receiving State is under a special duty to take all appropriate steps to protect the premises of the mission against any intrusion or damage and to prevent any disturbance of the peace of the mission or impairment of its dignity."
Since the US embassy is a greater security risk, India could be breaching its obligations by not taking steps it can take and which it had previously been taken, to protect those premises.
Now which chapter is going to unfold next and what will be the final outcome of this, only time will tell.