Brenden Aaronson is joining the most interesting club in Europe! How USMNT star will fit in at Union Berlin

That Union Berlin have found themselves in a strong enough position to sign a player of Aaronson's profile is startling, considering they were playing in the fourth tier of German football as recently as 2006. These fluctuating fortunes neatly sum up the Iron Ones' history as a whole. The current iteration of the club was formed in 1965, though their lineage can be traced significantly further back than that.

Located on the East side of the Berlin Wall, they were hardly a powerhouse in the German Democratic Republic, a fact made all the more jarring by their splinter team, that formed in West Germany after the Soviets banned the club from all-German competitions, enjoying significant success. The 10 successive league titles won by local rivals Berlin FC Dynamo - who had links to the secret police - similarly acted to strengthen Union's status as scruffy underdogs.

Being 'outsiders', if not entirely anti-establishment, is another key aspect of their identity. The dominance of Berlin FC made it easy for supporters to embrace this image, as did their ramshackle stadium, the Stadion An der Alten Forsterei.

"When I started going in 1973, the stadium hadn’t been expanded yet, so the fans were packed in tight and the atmosphere was really one of a kind," one fan recalled in a illuminating piece for Beyond the Last Man in 2018.

During the late 1970s, Union's reputation as a 'safe' haven for those in opposition to the GDR regime blossomed. Although there remained a degree of restraint, there was a growing tide of shrouded dissent at matches in this period.

A personal favourite of some supporters was chanting 'The Wall has to go' whenever a team had a free-kick in a dangerous position. There is also claims that shouts of 'Stasi Out!' and 'Sh*t Dynamo' were aired on the terraces.

Perhaps the most open defiance to the status quo was Union fans' friendship with Hertha Berlin. The two clubs were based on opposite sides of the Berlin Wall, but Hertha fans would travel to games when their own team was playing away, singing provocative songs en route to the stadium which claimed that two sets of supporters 'belonged together'.

The above led to the authorities monitoring sections of the Union support closely. Police records show that those of the red side of the Berlin derby were also more likely to be punished than their FC Berlin counterparts if there was ever crowd trouble - which there frequently was.

Despite all this, there are limits to Union's reputation as counter-culture hell raisers, according to several who were there. “The great majority of Union supporters were just normal fans. By the end of the 1980s, many people had had it up to here [with the GDR] and came to Union games to get their unhappiness off their chest," long-time fan Theo Koerner has recalled. "Union fans were always quick, but you shouldn’t make resistance fighters out of them. Provocation is a part of football and people yelled out whatever they knew they could get away with without too much trouble."

Following the reunification of Germany in the early 1990s, many GDR-based clubs found it extremely difficult to sustain themselves. Union were no different. Lumbered with a stadium that was in dire need of improvement and an unsavoury minority of far-right supporters, they seemed a million miles away from reaching the Bundesliga, let alone the Champions League.

Fumbling around in the third tier, a solution was eventually found for their infrastructure problems, with supporters reaching into their own pockets to fund the stadium redevelopment.

It was not the first time that Union fans had shown ingenuity to keep the club afloat. During a particularly worrying period, supporters would give their ticket money to shady go-betweens in the forest surrounding the stadium. This helped keep the revenue away from their creditors who were crawling all over the books, with the money instead being used to make much-needed improvements around the club.

Following decades of perilous instability, Union finally got themselves on an even keel in the 2000s. In 2006, they won promotion back to the third tier, but they were not there for long.

After finishing 12th and fourth, they romped to the 3.Liga title in 2009, with club legend Karim Benyamina netting 16 goals. His No.22 jersey was retired in 2011 and will only be worn again if someone is able to break his all-time scoring record.

Union had little trouble establishing themselves in the 2.Bundesliga following promotion, recording a string of mid-table finishes before flirting with promotion during the 2016-17 campaign. Although they eventually fell short, just two years later they would secure Bundesliga status, finishing third before beating fallen giants Stuttgart on away goals in a dramatic relegation play-off.

After the full-time whistle sounded, the pitch was flooded by Union supporters. It felt like things could not get any better. In fact, it was only the start.

Many expected Union to go straight back down, but they defied these gloomy predictions by comfortably securing a 11th-placed finish in a coronavirus-affected season. The following summer, they lost talismanic target man Sebastien Andersson, but fuelled by the goals of the volatile Max Kruse, they managed to improve their league standing by four places, clinching Europa Conference League football in the process.

Did the extra Thursday-night football affect them? Not at all. Once again they managed to rise even higher in 2021-22, qualifying for the Europa League courtesy of a top-five finish. They flew even higher last season, even briefly forcing their way into the title conversation. A quick start to the campaign, coupled with Borussia Dortmund and Bayern Munich struggling, meant Union spent seven successive matchdays sat pretty at the top of the pile.

Eventually, the pressure of European football would prove too much to handle and they dropped out of the title race. Union instead contented themselves with a place in the top four as well as a famous victory over Ajax in the Europa League. "It’s madness, it’s surreal," manager Urs Fischer reflected.

This is the part where you might be expecting us to reveal that this remarkable rise has been fuelled by some mystery financial backer with nefarious aims. You'll be pleasantly surprised that there is nothing of the sort happening at Union.

They are as close to a model football club as you will find in the Champions League next season. Member-owned, they have so far resisted the modern urge for a lucrative injection of morally-ambiguous cash. Their supporters are proud of this too, recently holding up a banner that read: "If being competitive means losing your values, we’d rather not be. Those who don’t get it, should go to Hertha."

Union's success boils down to two key factors: their supernatural hit rate in the transfer market and the undeniable talent of their unassuming head coach, Fischer.

Over the past few summers, Union have often had to contend with having their best players ripped away from them: Taiwo Awoniyi's move to Nottingham Forest is the latest example. And yet, every time, they have found a way to recover. For instance, after Awoniyi left, Sheraldo Becker stepped up, with the formerly unsensational forward plundering a career-high 11 goals last season.

That Becker was Union's top scorer with a total that scarcely breaks into double figures, speaks to another of the team's core strengths: Fischer's tactical acumen.

Union's success has been built on a rock-solid defensive foundation. Last season, they conceded the joint-fewest goals in the Bundesliga, and only 11 teams in Europe's top-five leagues had more success keeping the ball out of their own net. All of this was achieved with a backline assembled mostly on free transfers.

Fischer has achieved this by deploying a resolute 3-5-2 formation, which he used in almost every one of his team's games last season. Union do not press particularly high, unlike many other teams in the Bundesliga, instead opting to retreat into a mid-block.

Once in position, they work hard to retain a compact shape. In this way they are able to keep their opponents at arm's length, controlling their movement and marshalling them into less dangerous positions. Once there is an area or moment of weakness, they pounce in perfect unison.

The approach requires obsessive drilling on the training field, tireless hard work and sometimes, the deployment of the dark arts - only two Bundesliga teams committed more fouls than Union last season. It also makes them incredibly difficult to break down. Creative midfielders and wide forwards who like to move inside always struggle against Union. There simply aren't the pockets of space between the lines for them to cause their usual damage.

Once they have the ball, they tend not to wait around, using quick passing sequences to get it wide, either to their wing-backs or a forward who has pulled into the channels.

The ageless Christopher Trimmel at right-back has been one of the main beneficiaries of this approach, with the 36-year-old registering double figures for assists during both the 2019-20 and 2020-21 seasons. Trimmel also provided a significant portion of the 115 crosses into the penalty area his side attempted last campaign - with only Fiorentina and Inter registering more in Europe's top five leagues.

The final key tenant of Fischer's approach is his propensity to rotate, with the Swiss using 30 players in all during 2022-23. While their tactical approach is remarkably consistent, this chopping and changing makes it difficult for their opponents to prepare to face them.

There seems to be a few different options for Fischer when it comes to fitting Aaronson in the starting XI. Most obviously, he could slot into the midfield three, to the right of sitting midfielder and captain Rani Khedira - the brother of former Real Madrid star Sami.

While Janik Haberer made the left-sided central midfield role his own for the most part, the opposite side was more open. In this role, Aaronson's speed, stamina and discipline off the ball would suit the defensive responsibilities Fischer demands.

In possession, he'd also have the opportunity to drift wide and cross or arrive in the box at the opportune time to finish off a cross. In general, Fischer's charges are extremely active as soon as the ball is turned over, and Aaronson's wasp-like restlessness would be make him feel at home at Union.

It's not just in midfield where he could be useful. He may be used in one of the fairly fluid centre-forward positions or perhaps even a wing-back berth. However, his lack of physical strength - which became a bitter point of contention for Leeds fans towards the end of last season - would likely limit his effectiveness in these positions.

Regardless of where he ends up playing, it's clear that Union present Aaronson with a platform to get his career back on track following a sizable bump in the road last season. There are at least a few things to suggest that the transition need not be a painful one, too.

The Bundesliga has been a U.S. outpost in Europe for many years, and Aaronson will be linking up with a Union squad that already boasts two Americans: Jordan Pefok and Malick Sanogo. Bobby Wood, capped 45 times by the USMNT, also enjoyed a memorable spell there in the recent past. This American influence means Union will be well prepared to help Aaronson find his feet, even if he already has experience playing in central Europe with Red Bull Salzburg.

The decreased scrutiny compared to his experiences at Leeds will also be welcomed. The Whites are a huge club, one of the biggest in England and their fans have high expectations. When things started to slip last season, the atmosphere at Elland Road became challenging and at times it seemed like Aaronson wilted under this pressure. Even if their story is fascinating, there will be far less eyeballs on Union last season. As a result, we could witness a liberated Aaronson in Germany.

This is also a chance to prove he can live up to his lofty billing as one of the shining lights of the U.S.' golden generation. If he can do it in the Champions League, a permanent move next summer to a truly-elite side would not be out of the question.

Let's not get ahead of ourselves, though. Aaronson's reputation took a significant hit last season and, for now, it's simply time for him to show he belongs at the top level.