The German military is about to achieve its long-held wish to acquire its first weaponized drones – and is on the verge of persuading Angela Merkel's administration to pay for them.

Leaks to the Süddeutsche Zeitung in late May showed that the Bundeswehr requested €900 million ($1.04 billion) to lease five Heron TP drones from Israel over the next nine years – a significant upgrade on the Heron 1 surveillance and reconnaissance drones it currently leases.

The weapons the drones will carry are not part of the deal, and will be chosen once "comprehensive international legal, constitutional, and ethical assessments" have been made, according to the government coalition contract signed by Merkel's Christian Democrats and the Social Democratic Party (SPD) in February.

Read more: Germany draws up €450 million military wish-list

What are Heron TPs?

The Heron TP is the latest unmanned aerial vehicle (UAV) in the Heron series made by Israel Aerospace Industries (IAI), a company wholly owned by the Israeli government.

It belongs to the Medium Altitude Long Endurance (MALE) class, is 14 meters (46 feet) long, has a 26-meter (85-foot) wingspan, is capable of over 36 hours of continuous flight, and can reach an altitude of 12,500 meters – all of which makes it bigger and more powerful than the Heron 1, which the Bundeswehr currently leases. TP stands for turboprop, its 1,200-horsepower engine.

"It is similar in terms of capability to the Predator or Reaper drones that most people know from the US," said Ulrike Franke, drone warfare expert at the European Council on Foreign Relations (ECFR). "But the Predator is older and has been criticized by German engineers because it is not a particularly sophisticated system."

Many other militaries and police forces around the world use Heron drones, including those in India, Brazil, Canada, Greece, Turkey, and the US Navy.

Why does the Bundeswehr want them?

The Heron TP has been on the German military's wish-list for years – specifically because it can be armed, though there has been no information from government circles on the types of missiles it will be equipped with.

The Bundeswehr's surveillance and reconnaissance needs are all covered by the Heron 1, but according to Franke, drone pilots have long complained that they cannot protect ground troops when they come under attack.

"I've interviewed several German Heron 1 pilots, and they have testified how frustrating it can be to be above troops on the ground, and help them by telling them what's going on, and then when the troops are attacked, all they can do is let them know where they're being attacked from," she told DW. "I don't expect the German Bundeswehr to follow the US example in terms of targeted killings outside of official battlefields."

At the moment, the Bundeswehr would be most likely to use the drones in Mali and Afghanistan, where it is involved in international military operations.

What is the €900 million being spent on?

Given that Germany isn't so much buying the drones as buying flight hours with them, and that they "only" cost around €10 million each, €900 million seems like a lot of money to spend.

According to the Defense Ministry's latest report from March, most of the money, €720 million, would be spent on adapting the Heron TPs to German requirements, leasing the drones for a specific number of flight hours, training maintenance personnel, and the complete technical and logistical service of the drone over the nine-year period of the lease.

The other €180 million would be spent on a separate deal between the Bundeswehr and the Israeli military, which would see Germany pay for Israel's help with training, infrastructure, and stationing the drones at an Israeli airbase.

Why has it taken so long for the government to agree?

The German government is wary of strong criticism in Germany of extra-judicial killings carried out by US Army drones in the last decade, and both the last two coalition contracts mentioned specifically that the government "rejects killings that violate international law, including with drones."

That wording probably came from the junior partner in the coalition, the SPD, who blocked the acquisition of Heron TPs in the last legislative period. The Social Democrats have taken what Franke calls a "really weird stance" on armed drones.

"The SPD said it could only agree to a system that could be armed but not one that is actually armed," she said. "I think they only took that position before the election because they thought they could get some votes out of it. But now they have agreed because they realize it makes sense for Germany to have that capability too."

Why is Germany leasing rather than buying?

Germany's last venture into new military drone technology was a disaster, with theEuro Hawk projectsucking up €600 million in public money before being scrapped. The Heron TP is much less of a financial risk, since it is a tried-and-tested off-the-shelf system.

But Germany is determined to continue drone development, and in late April Defense Minister Ursula von der Leyen unveiled a plan to develop a brand new MALE systemwith France and other European partners.

The "Eurodrone," as it is still unofficially called, will be built by a Franco-German-Italian collection of companies (Airbus, Dassault Aviation, and Leonardo). The Heron TP is meant as an interim solution until that is ready - tentatively projected to be sometime in the mid-2020s.