Though I hesitate to second-guess Salman Rushdie's description of Indian law for Muslims (he being both India- and Muslim-born, and I neither), I do think that his Times op-ed leaves out some relevant historical political context as well as a federalism-esque rationale. He begins the piece by talking about two Pakistani gang-rape cases that have become famous, then says,
Now comes even worse news. Whatever Pakistan can do, India, it seems, can trump. The so-called Imrana case, in which a Muslim woman from a village in northern India says she was raped by her father-in-law, has brought forth a ruling from the powerful Islamist seminary Darul-Uloom ordering her to leave her husband because as a result of the rape she has become "haram" (unclean) for him. [...]
Why does a mere seminary have the power to issue such judgments? The answer lies in the strange anomaly that is the Muslim personal law system - a parallel legal system for Indian Muslims, which leaves women like Imrana at the mercy of the mullahs. Such is the historical confusion on this vexed subject that anyone who suggests that a democratic country should have a single, unified legal system is accused of being anti-Muslim and in favor of the hardline Hindu nationalists.
Probably because of space constraints, Rushdie fails to mention the history underlying this peculiar dual system, which dates back to 1937 and British colonial rule. Aware of the fate that a minority group that once had dominated the majority often suffers, the Muslim League boycotted the Hindu-led independence movement and called for a separate homeland. Majority acquiescence to the separate law is likely to be founded in a desire to prevent any more sectarian conflict than India already suffers.
When India was divided into Hindu and Muslim portions at its independence, the resulting chaos of forced migration -- fifteen million people's trying to move into the correct nation -- resulted in ethnic cleansing, riots and rapes. Hundreds of thousands of people died, including women who boarded cross-border trains; their relatives would go to meet them, only to find their severed breasts and dismembered bodies inside the cars. The violence continued almost undiminished with the three India-Pakistan wars, and the second half of Rushdie's own Midnight's Children recounts some of the worst horrors of the period, although I would consider the most emotionally wrenching part of the book to be that which deals with the Emergency called by Indira Gandhi. She later was killed by her own Sikh bodyguards, who sought to avenge the destruction of their faith's Golden Temple by government troops who were flushing out rebels hiding in the shrine. Several thousand Sikhs were killed in the attacks that followed.
By that standard, even the 1992 Bombay and 2002 Gujarat riots, each of which killed almost a thousand people -- mostly Muslims -- are blips on the tragedy radar. Bombay was touched off when Muslims there heard that the Babri Masjid mosque had been demolished by Hindus, who believe that it was built on the birthplace of the god Ram. Ten years later, a train full of Hindus who were going to Ayodhya to build a temple on that site was torched; Muslims were believed to be responsible, and their homes and businesses were destroyed. In both incidents, the ability of Hindu mobs to pinpoint where Muslims lived and worked indicates involvement by government officials.
Everyone knows about the ongoing tension between Pakistan and India and fighting in Kashmir, and I won't get into the separatist movements by Sikhs, Christians and Communists (just so the theists aren't having all the fun). Indian law has a hellishly difficult time dealing with the competing demands of various groups. Several states prohibited "forced conversions" due to hysteria that Christian missionaries were somehow tricking or bribing people into abandoning Hinduism.
My point is that the Indian government does not accede to the Muslim Personal Law out of complete disregard for how it treats women, but out of worries about what the reaction to ending it would be. Calls to get rid of it have become negatively associated with rightwing groups because they are the same people who destroyed the Babri Masjid mosque and now attempt to build a temple on its ruins -- i.e., folks with a questionable reputation even in progressive anti-sharia Muslim circles.
Faced with overseeing a country of not just diversity but longstanding animosity between various groups, the Indian government has resorted to something a bit like federalism. The American Founders united a country that was part free and part slave, of thirteen colonies with different preferences, by making several accommodations. The importation of slaves could not be banned until 1808; they would be counted as three-fifths of a person for taxation and representation; if they fled into another state, they had to be delivered back into slavery. The federal government's lawmaking power was restricted, while that of the states was comparatively unlimited, not even bound by the Bill of Rights until post Civil War 14th Amendment incorporation. Louisiana continues to be governed by a civil code rather than common law, stemming from its French heritage. Native Americans have their own constitutions and tribal codes because of their sovereignty within the U.S.
Such localization exists in India partly through the panchayat system of informal village leaders who help to maintain law and order, but who also often are far more "backwards" than the state or national government would be. Such behavior is not exclusive to Muslims; when a Hindu girl was raped and impregnated by a Hindu boy, her parents demanded that the rapist be punished, but the panchayat told him to marry the victim (once she became of age to be married, which she apparently was not yet).
As Ikram pointed out,
India has The Parsi Marriage and Divorce Act, the Indian Christian marriage act, the Hindu marriage act, the Hindu Maintenance and Adoption Act and special acts for intercommunal marriages. Beyond that, 'customary law' applies to many communities. For example, Keralan Muslims are not subject to the Shariat application act, they are instead governed by the "marumakkathayam" system. In Jammu and Kashmir , 'customary law', not sharia applies. In Goa, all citizens are governed by Portuguese family law. Tribals, Gujurati Bhoras, and many other all have thier own personal law systems.The intercultural and cross-national demand that all people have the same rights is not directed only at the developing world; for those who believe that one should be able to marry regardless of a spouse's gender, the idea of that this should not be enforced by the federal government seems a surrender on human rights. American history indicates an increasing uniformity of law, but this is not an uncontroversial development.
Ideally there should be one law for everyone within a nation regardless of their religion, so that the faith of one's fathers does not become an unjust trap. However, I do not think that a single, unified legal system will be achieved easily in India. In particular, Muslims must articulate that their democratic preference is be freed of the rule of mullahs; liberating them through a Hindu majority's law-making is likely to lead to massive unrest due to a perception that the minority again is being tyrannized over.