Space will be limited when Economy Minister Sigmar Gabriel's airplane takes off from Berlin to Tehran on Sunday. There will be 37 business representatives accompanying him on the flight - and more joining them once the plane lands in Iran, for a total of about 100 businesspeople taking part in discussions. Another 37 journalists will be on hand to record how the minister, who is also vice chancellor and head of the Social Democrats, will manage a 48-hour balancing act.

The purpose of the trip is to "position the German economy one year on from the nuclear agreement," said Rudolf Gridl, who specializes in the Middle East and North Africa at the Economy Ministry. "We are very confident that contracts or letters of intent will be signed."

Germany's relations with Iran have changed dramatically in the past year . After years of Iran's economic isolation, negotiations between Iran and the P5+1 - or the five permanent members of the UN Security Council (Russia, China, the United States, France and Britain) plus Germany - succeeded in  a wide-reaching easing of sanctions in return for the country's pledge to scale back its nuclear program and submit to international inspections. Once the agreement was reached, Gabriel became  the first EU minister to visit Iran, and other German politicians have been quick to  revive the previously good relations between the two countries.

"There's a very large interest from the German side," Gridl said. "All the German federal states have already sent delegations separate from this trip happening now."

'Up to speed'

The main lingering problem is that the United States has only partly relaxed its sanctions. Iran can export oil and gas again, as well as access long-frozen assets, but a US embargo remains in place. That makes international banks and business, including some in Germany and France, hesitant to invest in Iran. A dozen years of sanctions have resulted in Iran's banks lagging behind international standards.

"The federal government tries to provide Iran technical help in regards to bringing its banking sector up to speed," Gridl said.

There are high expectations, especially in the power, transport and health care industries. Many of Iran's hospitals are dilapidated and require international knowhow.

At the same time, there are nonbusiness aspects to consider. Iran has a negative human rights record, even under pragmatic President Hassan Rouhani. There are more executions now than there have been for many years. Ayatollah Ali Khamenei recently made headlines with a fatwa that banned bicycling in public for women, calling it corruption of society. Any mention by Gabriel of Iran's support for Syria's ruler, Bashar al-Assad, would be particularly sensitive.