Qatar-Gulf feud: What's next after the deadline?

They were friends. More than just friends, they were often family, quite literally. Saudi Arabia and Qatar were even allies in a war.

Then US President Donald Trump stepped in, issueing sweeping statements against Iran, multi-billion dollar defence deals and promises to back the Saudis and Emiratis if they were to bring long-simmering neighbourhood grievances out into the open.

Now Qatar has fallen out of favour with a bloc of mostly Gulf countries. Led by Riyadh. Saudi Arabia, the United Arab Emirates (UAE), Bahrain and Egypt, they severed diplomatic ties with Qatar last month. Those states cut off marine and air access and put restrictions on their citizens from travelling to Qatar.

And a deadline looms. Qatar has till Tuesday night to abide by a list of 13 demands.

The Riyadh-led bloc, which also includes Libya, Yemen and the Maldives, wants to force the influential Al Jazeera international news network to go off air. That was one of the key demands in the list that surfaced on July 23.

The Qatari state-funded broadcaster is at the centre of the crisis and has been accused of supporting dissent in neighbouring Gulf countries, especially in the wake of the uprisings that shook much of the Arab world in 2011.

The demands also include closing of a Turkish military base in Qatar, scaling back relations with Iran and discontinuation of support for Hamas and the Muslim Brotherhood.

It remains to be seen where this unprecedented drama might lead. Here we outline the most likely scenarios.

Could the Qatar-Saudi row end up with Saudi tanks rolling across the border?

That's an unlikely outcome for a crisis that has pitted a small but very rich country against its bigger, and also rich, neighbours.

Qatar and Saudi Arabia have had border skirmishes in past. Roots of that conflict go back to a time when Riyadh was used to dominating the Arabian Peninsular and viewed Doha as a rebellious younger sibling.

In 1992, three Qatari soldiers were killed when Saudi forces attacked a Qatari border post. The Saudis claimed it was a merely a dispute between feuding Bedouin tribes.

But shortly after this, Doha deepened military ties with the US – a shrewd move that coincided with the tiny country asserting a far more independent foreign policy, and its launching of the revolutionary Al Jazeera network.

After Iraq invaded Kuwait in 1990, "it became clear that the Saudis were unable to defend their borders, let alone the small satellite states within its political sphere of influence," writes Tarek Cherkaoui, a Doha-based analyst.

The result of cooperation with Washington was the Al Udeid air base, the largest US military installation in the region where around 10,000 American soldiers are stationed.

In the first few days after the GCC feud broke out, the Riyadh bloc's rhetoric became more hawkish. The UAE asked the US to move the Al Udeid military base to its soil but Pentagon was quick to clarify that it had no plan to change its position on Qatar.

The UAE has since toned down its rhetoric, saying in event of Doha's refusal to back down, it will face more economic sanctions and be further alienated, but that military moves against Qatar are out of the question.

"We can escalate with more information, because we are not going to escalate militarily. That is not the way we are looking at things," Omar Ghobash, the UAE ambassador to Russia, told The Guardian.

A breach between the Gulf countries can play out in other ways. For instance, in Yemen. Qatar has been part of the Saudi-led coalition fighting Houthi rebels in a harsh bombing campaign against the impoverished country.

The crisis, however, has likely pushed Doha closer to Iran, which is accused of backing the Houthis, militarily and financially.

What about imposing an economic embargo on Qatar?

That's probably on top of the anti-Qatar club's agenda.

UAE's Minister of State for Foreign Affairs Anwar Gargash has already talked about economic curbs if tensions persist.

There won't be any "big bang" after the deadline ends, he told CNN, but rather a gradual "turning of financial screws" will take place to put pressure on the Qataris.

Perhaps to shake the confidence of international investors, the Saudi-UAE leadership says fresh sanctions could include asking trade partners to choose between Qatar or them.

But that's easier said than done.

The consequences of the rift have already been felt in Qatar where the riyal has faced fluctuations.

The local stock market plunged 3 percent on Sunday, a day before the deadline was supposed to expire, and multinational companies are worried about their Gulf operations.

The bloc has already severed land and air ties with Qatar.

Restriction on the transportation of goods from Saudi border was particularly severe since Qatar relies on the route for most of its food imports.

The closure of airspace to Qatar by countries of the Saudi-led bloc not only disrupted Qatar Airways' ambitious expansion plans but added to its costs. Dozens of its flights to Dubai and other cities in the estranged countries have been cancelled.

Its jets also have to take different routes, through Iranian airspace.

Is the economic embargo enough to force Qatar into submission?

That remains to be seen.

Immediately after ties were cut with Qatar, freight trucks carrying basic items started to pile up at the closed Saudi border. There was panic in stores in Doha as people rushed to stock up.

But within days, shelves had milk, butter and cheese – flown in from Turkey.

Qatar, the world's richest nation on a per capita basis, is among the few countries which can afford to fly in goods without worrying about the trade deficit too much.

Its sovereign wealth fund has assets of $335 billion. Over the years, it has invested in companies ranging from the Russian oil giant Rosneft, British bank Barclays, American luxury retailer Tiffany, French fashion house Balmain to German automotive giant Volkswagen.

The ramifications of possible sanctions on these investments is not known at the moment.

Qatar is world's largest supplier of liquefied natural gas (LNG). Japan, South Korea, India and China are its largest buyers.

How exactly these powerful countries would react to any demands to cut ties with Qatar is also difficult to foresee at this stage.

India has around six million expats in the Middle East, many of them working in Saudi Arabia and the UAE. But it also has close relations with Qatar and Iran.

While Japan imports gas from Qatar, it also sources most of its crude oil from Saudi Arabia.

"In energy security terms, the growing rift between Doha and its neighbors in the Gulf should raise alarm bells in Tokyo and further push forward moves to diversify its energy supply sources," wrote Jonathan Miller of the EastWest Institute for Nikkei Asia.

Even UAE imports LNG from Qatar.

Qatar's major imports comprise aircraft, parts and cars.

Because of its dominant position in the LNG market, the country runs a trade surplus, easily allowing it the room to import goods which other Gulf countries are threatening to block.

Is Qatar being pushing out of the GCC?

Qatar would be pushed out of the Gulf Cooperation Council (GCC) if it continues to hold its ground after the extended deadline expires.

The organisation that includes energy-rich Saudi Arabia, UAE, Qatar, Kuwait, Oman and Bahrain was formed in 1981.

The GCC has remained stable for most of its life, acting to back ruling elites when members such as Bahrain faced internal protests and the group approved sending Saudi-led troops to suppress dissent there in 2011. Qatar, Kuwait and Oman refused to intervene then.

In Yemen, an aspiring GCC member, the GCC has aggressively intervened both politically and militarily. Oman was the sole dissenter in the GCC over the military intervention.

It faced fissures in 2015 when Saudi Arabia, UAE and Bahrain withdrew diplomats from Qatar, in a crisis similar to the one that continues these days.

Qatar hasn't backed down from pursuing its own foreign policies, especially when it came to relations with countries outside the GCC.

For instance, Turkey deployed troops in Qatar, days after the Saudi-led bloc announced sanctions.

It has also refused to realign its policy over Iran.

The crisis has pushed Muslim countries outside of the GCC to take sides.

Egypt, where President Abdel Fattah el Sisi's regime abhors the Muslim Brotherhood, has been a cheerleader for Riyadh.

Others, such as Pakistan, which has one of the most powerful militaries in the Muslim world, has found itself in a tight spot. Pakistan is so far striking a balancing act by maintaining close relations with both Riyadh and Qatar.

So what about the demands?

Qatar has refused to give in, saying the demands were made to be rejected.

Al Jazeera does not seem to have altered its editorial policy as it continues to critically examine the crisis, Turkish reinforcements have increased, and relations with Iran remain as they were.

In the immediate aftermath of the diplomatic rift in early June, Doha reportedly asked Hamas and Muslim Brotherhood leaders to leave. But it remains to be seen if Qatar has shifted its policy in any substantial way.