It was an adventurous, long, and arduous journey for Total CEO Patrick Pouyanné and Iranian oil minister Bijan Namdar Zanganeh to sign an agreement Monday on energy production of great importance to both sides.  For Iranian president Hassan Rouhani, who has just started his second term after the May 19 presidential election, the July 3 signing is the first foreign investment after the July 2015 nuclear agreement (aka the Joint Comprehensive Plan of Action).

"We will never forget that Total was the precursor," Zanganeh said at the signing ceremony of the agreement, before adding, "We will not forget our friends during difficult days."

"Today is a historic day for Total, the day we return to Iran," said Pouyanné, adding, "We are proud and honored to be the first international company to sign the Iran Petroleum Contract with Iran."

Under the terms of the 20-year contract, the consortium will invest $4.8 billion to develop phase 11 (of 24) of Iran's South Pars offshore gas field.

South Pars, coupled with Qatar's North Dome, is the largest discovered natural gas field in the world.

Total will hold 50.1% of the consortium shares, followed by the China National Petroleum Corporation (CNPCI) with 30% and Iran's Petro Pars with 19.9%.

Phase 11 of the South Pars gas field will be developed in two stages.  The first (in 40 months), estimated at $2 billion (half of which to be provided by Total), will see the drilling of 30 wells, construction of two platforms, and the installation of two connection lines to existing shore-processing facilities.

"It's worth taking a billion-dollar risk because it's a huge market," says Pouyanné, prior to highlighting the slogan of this contract.  "We have to live with a certain degree of uncertainty."

Political circumstances confirm the uncertainty that hangs over this contract, which could be undermined by two major threats.

What has gone overlooked by many is the fact that Washington is re-examining its Iran policy, raising many doubts about the JCPOA's future, according to many observers.  The U.S. Congress will most likely adopt new sanctions that could challenge this agreement.

But a second threat is even more chaotic, involving Iran's domestic political instability, consisting of several factors:

- Rouhani is in disarray with the camp loyal to Iranian supreme leader Ali Khamenei.  In recent weeks, the scale of this confusion has advanced the idea of setting Rouhani aside from his office.

- The supreme leader and his entourage fiercely oppose this type of IPC contract, which replaces Buyback contracts and allows foreign investors to share in the total gas production.  In remarks last year, Khamenei specifically opposed this type of contract.

- Senior Khamenei camp officials often compare the IPC to the 1828 Turkmanchai Treaty, under which the Persian Empire lost its northern territories.  They even emphasized that the IPC is in violation of the Iranian constitution and the rights of Iran's National Petroleum Company.

- Another very destabilizing factor is determining Khamenei's successor.  This dispute has remained behind closed doors, yet it is no less the engine of a tug-of-war at the head of the seraglio.

Total is entering the Iranian market mine field.  It is worth recalling that Pétropars is a branch of Niko (the Naftiran Intertrade Company), which has been deeply involved in money-laundering and financing for the Revolutionary Guards in recent years, and the regime's missile development program.

Washington entered the company onto the list of sanctioned facilities in 2010, 2012, and 2013.

If Total's $1-billion bet in Pars-Sud fails, it will not be a big surprise.  But if it happens, it will be really fascinating, as it will involve a whole series of political and economic openings that themselves involve many other changes.

Mohammad Amin (@EconomieIran) is a senior research fellow for the Paris-based Fondation d'Etudes pour le Moyen-Orient (FEMO) or Foundation for the Study of the Middle East.  He has written several books and essays about the ruling theocracy, the transformation of Iran's political economy under the presidency of Mahmoud Ahmadinejad, and the rise of Islamic fundamentalism in the Middle East.