New York - One is a vegetarian, yoga fan. The other eats steaks like they're going out of fashion.
This does not mean that Monday's first meeting between Indian Prime Minister Narendra Modi and US President Donald Trump will be awkward. Aides on both sides have billed it as a chance to strike up a friendship.
The two men have much in common - they are both populist, pro-business nationalists who rocked their respective political establishments. Each has amassed more than 30 million Twitter followers.
Such similarities can come in handy when they get down to business in White House talks on everything from arms, trade and visas, to global and regional security challenges.
"The summit will be a no-frills, let's-get-acquainted affair," Michael Kugelman, a scholar at the Woodrow Wilson Center think-tank, told Al Jazeera, before the half-day of sit-downs, cocktail reception and working dinner at the White House.
"Its outcomes, from body language to any post-meeting joint statement, will offer clues about the future of ties that have progressed in recent years, but now face considerable uncertainty under Trump's mercurial stewardship," he said.
'Guns to sell, guns to buy'
Arms deals could buoy the chat. India has signed $15bn worth of defence contracts with the United States since 2008, a White House official told reporters on Friday, on condition that their name was not used.
"These are people with guns to sell and guns to buy," Vijay Prashad, a Trinity College scholar, told Al Jazeera.
Lockheed Martin, a US military aerospace firm, is negotiating with India's Tata Advanced Systems to shift production of F-16 fighter jets from the US to India as part of a deal to supply the Indian Air Force with hundreds of new aircraft.
Washington is also set to confirm the sale of 22 unarmed Guardian drones, a naval variant of the Predator, which New Delhi wants to deploy to Indian Ocean waters where China is expanding trade routes and sending submarines.
"If approved, India will become the first non-NATO country permitted to buy hi-tech, unmanned Guardian drones, and the US would net an estimated $2-3bn, which will doubtless smooth the path for closer cooperation," Lindsey Ford, a former adviser to the US Department of Defense, told Al Jazeera.
Trump and Modi see eye-to-eye on security.
Both leaders vehemently decry "Islamist extremism". Trump may ask Modi to formally join the US-led coalition against the Islamic State of Iraq and the Levant (ISIL, also known as ISIS); Modi may call for tougher US action against anti-India fighters in Pakistan.
Trickier issues - such as Iran, Afghanistan and Pakistan - may be skirted around. Washington still has 8,000 troops in Afghanistan and is conducting a review into its 16-year-old war that will not be finished until mid-July.
New US plans may entail using aid and a threat of downgrading US-Pakistani ties to crack down on Pakistan-based fighters launching attacks in Afghanistan. New Delhi, likewise, blames Islamabad for armed attacks on its own turf.
"The US has sought Indian help with its adversaries," said Prashad, the Trinity College scholar.
"While the US has its agenda, India cannot become a full-scale US partner because of so many contradictions in the region. It has its own strategic landscape to attend to."
'Make in India' vs 'America First'
There are also problem areas. Modi is likely to raise concerns over a visa scheme for bringing high-skilled foreign workers into the US, including many of the Indian tech whizzes who work in Silicon Valley.
Trump, who campaigned on an anti-immigrant platform, has ordered a review of the H-1B programme, threatening Indian IT services firm such as Infosys Ltd and Tata Consultancy Services, which advise and assist big firms on tech issues.
The former reality TV star also told voters he would level up America's trade deficits, and has since launched investigations in trading patterns with countries, including India, which sell more to the US than they buy.
US-India trade more than doubled from $45bn in 2006 to about $115bn last year, but the US trade deficit also widened to $31bn in that time.
This is where economic nationalism stirs tensions, said Kugelman, the Woodrow Wilson Center scholar.
"The clashing objectives of Modi's 'Make in India' - which calls on foreign firms to operate in India - and Trump's 'America First' - which asks US firms to stay home - portend possible bilateral irritants that are better off not surfacing in this maiden meeting."
Global warming is another sore point. After the US pulled out of the Paris Climate Agreement, Trump accused New Delhi of trying to extract "billions and billions" of dollars in foreign aid in exchange for signing the accord.
Life for some four million Indian Americans and the 166,000 Indians who study in the US may also come up. Trump's anti-immigrant rhetoric has been linked to spikes in racial violence, including the killing of Srinivas Kuchibhotla, a 32-year-old engineer, in a bar in Kansas in February.
'I buy from you, you buy from me'
Successive US presidents have tried to woo India to counterbalance China's growing regional clout. Trump met Chinese President Xi Jinping in April to enlist help on halting North Korea's nuclear arms programme, but managing Beijing's rise remains a priority for the US and India, said Kugelman.
White House staffers admit they are fighting perceptions in New Delhi that India is not a priority for Trump, who has also had face-time with the leaders of Japan, Britain, Vietnam, Saudi Arabia and Egypt, among others.
"It would be wrong to say that this administration has been ignoring or not focused on India," the White House official said.
This undermines the "strategic partnership" that previous US administrations built, said Aparna Pande, a Hudson Institute think-tank analyst. There are enough "fault lines" between Trump and Modi to roll back progress.
"It will become more transactional: 'I buy from you, you buy from me'," Pande told Al Jazeera.
Anubhav Gupta, from the Asia Society Policy Institute, said Trump "badly needs an opportunity to bolster his presidency", which has been rocked by claims that his campaign staff colluded with Russia to tip last year's election in his favour.
"India's fast-growing, increasingly open economy offers big opportunities for the US … but success hinges on whether Trump's team can focus enough attention on India and decide whether and how it wants to upgrade ties," Gupta told Al Jazeera.
For Alyssa Ayres, a former US Department of State official, Modi's two-day visit to Washington, which begins on Sunday, is not likely to herald breakthroughs in a US-India relationship that has had its ups and downs.
"US-India ties have been plagued by expectation of what the next big deal and big idea will be," Ayres told Al Jazeera.
"Both governments are messaging that this summit is about building a personal relationship and finding an equation between two men that's comparable to the good working relationship Modi had with [ex-US President Barack] Obama."
Follow James Reinl on Twitter: @jamesreinl