Just outside the main complex of the shrine where the samadhi and the grave of Guru Nanak, the founder of Sikhism, are believed to be located is the sacred well from where Guru Nanak used to draw water for his fields. After a long pilgrimage of almost three decades, the guru finally decided to settle at this spot, now called Kartarpur Sahib, near the city of Narowal in present-day Pakistan.

He lived here for 17 years and appointed his disciple Bhai Lehna (Guru Angad) as the next guru before passing on to the next world. According to legend, an argument arose after his death between his Hindu and Muslim devotees as to how to perform his funeral rites. The Hindus wanted to cremate him, while the Muslims wanted a burial. Night fell while they were still arguing so both the groups decided to resolve the matter in the morning. When they woke the next day, they found that the body had disappeared and there was a heap of flowers at the place where the body was. Dividing the body of flowers into two, the Muslims buried them while the Hindus cremated them. This is why the shrine of Guru Nanak has a grave and a samadhi.

Next to the well, enclosed within a glass case, is a bomb. A plaque next to it says that during the India-Pakistan war of 1971, the Indian Air Force dropped this bomb to destroy the shrine. However, due to the blessings of Waheguru (with Allah within brackets), the bomb fell straight into the well and thus the shrine remained unharmed.

A few kilometers from here is the most dangerous border in the world: the India-Pakistan border. Here, there is a darshan sthal, which allows pilgrims on the Indian side of the border to catch a glimpse of the final resting place of Guru Nanak through binoculars. In the late 1990s there was talk of the construction of a corridor that would enable Indian pilgrims to travel to Gurdwara Kartarpur Sahib without a visa or passport, a proposal that was accepted by Pakistan, but rejected by India.

Gurdwara Kartarpur Sahib symbolically represents extraordinary religious syncretism, and the proposed cross-border passageway to the gurdwara has been held up as a prospective corridor of peace in South Asia with the potential of bringing the two nuclear-armed nations together.

However, such an understanding of the shrine represents a surface-level reading of the situation. Instead of being a corridor of peace, the shrine in fact represents a further crystallisation of religious and national identities in both countries. It reflects the deep hostilities that run between the two arch-enemies, and how Sikh heritage is now held hostage in the middle.

About 500 km from here, in the city of Hassan Abdal that straddles the provinces of Punjab and Khyber-Pakhtunkhwa, is another historical gurdwara dedicated to Guru Nanak. Gurdwara Panja Sahib is built around a rock that is believed to have an imprint of Guru Nanak's hand. The rock was hurled at him by a Muslim saint sitting on the top of the mountain too arrogant to give travelers a share of his water. Performing a miracle, Guru Nanak took the saint's water from him and a stream started flowing at the base of the mountain, where the gurdwara is now located.

I first visited that gurdwara in April 2011 to attend the annual fair of Vaisakhi that is attended by thousands of devotees from both sides of the border and beyond.

Here I came across a 30-year-old Sikh man from Peshawar wearing a white T-shirt with a picture of Jarnail Singh Bhindranwale on one side and the text Never Forget 1984 on the other. A fiery religious leader, Bhindranwale became the symbol of Sikh militancy in the 1980s and '90s in East Punjab. He was killed in a military operation on Harmandir Sahib (the Golden Temple) in June 1984, which fuelled passions for a separate Sikh state of Khalistan and also resulted in the assassination of the Indian Prime Minister Indira Gandhi.

This T-shirt, in different colours, was available for sale in the stalls behind the gurdwara. Since then I have seen this Bhindranwale image at different gurdwaras around Pakistan on the occasion of several religious festivals.

In the same year, in the month of March, I happened to visit Gurdwara Janamasthan at Nankana Sahib, the birthplace of Guru Nanak. A few hundred local Sikhs had gathered there to celebrate the Sikh New Year.

After the conclusion of religious ceremonies, a local, passionate Sikh leader from the community took the pulpit and spoke vehemently against the Hindu influence over Sikh religious offices in East Punjab (in India). The bone of contention was the implementation of a new calendar for the Sikh community. The drafting and the implementation of this new calendar was a product of the Khalistan days - a bid to exert a separate Sikh identity from Hinduism. However, still haunted by the days of militancy, the Punjab government, exerting its influence over Sikh religious bodies, forced them to reject the new calendar. This was being protested that night at Gurdwara Janamasthan.

The scene was reminiscent of the 1980s and 1990s when prominent international proponents of the Khalistan movement, banned from India, used to come to Pakistan regularly on the occasion of Sikh religious festivals and make powerful speeches against the Indian government, heard by thousands of Indian pilgrims. Banners in favour of Khalistan used to be strung all over these gurdwaras.

It was around this time that the Pakistani government warmed up to these Sikh leaders both of whom shared a hatred for the Indian government. These Sikh leaders lobbied for the renovation of their historical Sikh gurdwaras in Pakistan. In the next few years, a process that continues till today, several old Sikh gurdwaras were opened and handed over to the local Sikh community, who felt empowered and heard for the first time. Whereas the riots of Partition in West Punjab had severed the relationship between Muslims and Sikhs in Pakistan, the Khalistan years once again brought them together, as they found a common enemy in the form of Hindus.