India's long, porous Himalayan border with China was, from the moment of its founding as an independent nation, a source of cross-border tension. In the winter of 1962, those tensions finally descended into a shooting war.
The war of 1962 was brief, lasting barely a month and was won decisively by the Chinese side, a humiliation that India has never forgotten and which continues to factor into defence and foreign policy considerations. Yet the war was also notable for being the moment that relations between India and Israel began to thaw.
In October of that year, aware that the conflict was going badly, Israel offered then Indian prime minister Jawaharlal Nehru a shipment of arms and ammunition. Mr Nehru agreed but asked that the shipment be made under plain cover so as not to antagonise India's Arab allies. David Ben Gurion, then Israel's prime minister, first delayed and then refused, forcing Mr Nehru to back down. The Israeli arms were delivered but the war was still lost.
That incident became the starting point for Indian-Israeli relations. Yet for decades, India was reluctant to embrace Israel. Although it recognised Israel in 1950, it refused to establish diplomatic relations for more than 40 years. Finally, in 1992, against the background of peace talks with the Palestinians, India formally established ties. Yet relations were still slow; it was another 11 years before Israel's first prime ministerial visit to India and only last year that Narendra Modi became the first Indian prime minister to visit Tel Aviv.
That deep reluctance points to something else in the India-Israel relationship, which was glossed over during the initial love-fest between Mr Modi and Benjamin Netanyahu in New Delhi this week. India wants a relationship with Israel but not for the same reasons Israel does. For all the talk of common bonds between the two countries, Mr Modi's eyes are firmly fixed on his own backyard. He is not looking to get entangled in conflicts far from home.
Although Mr Modi has made the right noises towards Israel, he has also put clear water between the two countries at important moments. He decided to vote against recognising Jerusalem at the United Nations last month and days later – and of greater concern from an Israeli perspective – he cancelled a deal for thousands of anti-tank missiles. The $500 million deal represented half of Israel's sales to the country last year, a serious blow to the country's industries.
Arms matter to Israel. Israel's defence industries desperately need clients; those who can afford the more sophisticated European or American weaponry buy those and those who have closer relations with Russia and China shop there. But arms are also how Israel traditionally makes allies, forging political links through defence ties.
Israel has repeatedly sought to use weapons' sales as a foothold for diplomatic relations. The reason Israel deals with countries like Myanmar and South Sudan is because few other countries will. But India is not in the same position. New Delhi has good relations with the Arab Gulf states, Turkey and Iran and is unlikely to jettison those simply to acquire weapons.
Without robust defence sales, then, Israel's relationship with India will be limited to being a trading partner rather than a strategic ally.
Certainly, India imports a huge number of arms. Indeed, according to the Swedish International Peace Research Institute, it was the world's leading importer of arms between 2011 and 2015, accounting for nearly 15 per cent of all imported weaponry. But India wants to change that. Wary that China, which also imports a lot of arms, has poured money into research and development, it wants to focus on its own domestic weapons.
The Israel deal was for Spike anti-tank missiles but reports in the Indian press quoted defence ministry officials, who believed India could match Israel's anti-tank technology within three years.
That has two implications for the Israeli relationship. The first is that, simply put, India will have little need for Israeli missiles when it is capable of building its own. But the second is of greater consequence. If Israel cannot forge an arms-first relationship with New Delhi, it might not be able to forge the sort of diplomatic relationship it really wants.
Tel Aviv would like India as a diplomatic heavyweight fighting its corner against the Palestinians. For Mr Modi, that conflict is a long way off. He is much more concerned with a potential conflict on his doorstep.
It is China that India is in competition with. In 2016, India spent $50 billion on its military. China spent $226bn. The disparity is vast and growing. Pakistan is also increasing its spending, last year showcasing submarine-launched cruise missiles and experimenting with multiple nuclear warhead missiles. But the story doesn't end there because Pakistan is not only buying arms, it is buying a lot of them from China. India's two biggest regional rivals are therefore locked into military cooperation which excludes it.
It gets worse. China's enormous $1 trillion One Belt, One Road initiative will eventually link dozens of countries to China through a series of land and ocean corridors. India is the only south Asian country not involved (partly at New Delhi's behest). The plan will link the countries to the east and west, Pakistan and Bangladesh, leaving India isolated.
So New Delhi is looking for allies who can provide political support and sophisticated weaponry but only those it can't develop itself. The lesson of 1962 is that it is much better to have the arms in the first place rather than having to buy them in.
That puts Tel Aviv in an awkward position. For Israel, India is a way to break out of its isolation in the Middle East and find allies further afield but it needs the defence relationship first. This is where India's reluctance to buy arms bumps up against Israel's strategic goals.
That's why Mr Netanyahu sought to put a brave face on the two most recent disappointments – the no vote on Jerusalem by India and the cancellation of the arms deal – by saying in New Delhi this week that he was "naturally disappointed" but that the India-Israel relationship would move forward.
For now, Indian-Israeli ties matter more to Tel Aviv than they do to New Delhi. India's interest in Israel has little to do with the Middle East and everything to do with its own territory. It needs allies in preparation for its own confrontations with its neighbours, not to get involved in the confrontations of others. As much as Mr Modi will put on a warm show for his guest, he cannot offer Israel the brothers-in-arms relationship it truly wants.