Radiating anger and resignation in equal measure, Arsene Wenger wore the exasperated expression that has become all too familiar to Arsenal followers during their club's futile attempts to conquer Europe.

Wenger's frustrated demeanour on the touchline at the Allianz Arena last month was provoked by the sight of Arsenal being outclassed by Bayern Munich -- again -- in the first leg of their Champions League last-16 tie.

Each Bayern goal was a fresh twist of the knife for Wenger and by full-time Arsenal had been hammered 5-1, a chastening loss that seems certain to make Tuesday's second leg at the Emirates Stadium a mere formality for the Germans.

There was an unmistakeable feeling of deja vu as Wenger and his players trudged back to the changing room, once again assailed by the harsh realities of Europe's elite club competition.

Arsenal have been eliminated in the first knockout round of the Champions League in each of the last six seasons, twice by Bayern, and Wenger appears no closer to solving the problem.

This season's likely exit would sting even more for Wenger because it could prove his final taste of the Champions League after 21 years as Arsenal manager.

Amid mounting speculation Wenger is ready to quit when his contract expires at the end of the season, the Frenchman has refused to give a firm assurance he will return next term.

If that is the case, his failure to master the unique demands of the Champions League will surely be Wenger's biggest regret.

Wenger was just 14 minutes from lifting the trophy in 2006 when Arsenal led Barcelona despite the dismissal of goalkeeper Jens Lehmann.

But Sol Campbell's goal for the Gunners was relegated to a footnote as Barca's pressure finally paid off with late strikes from Samuel Eto'o and Juliano Belletti.

- Inferior again -

That Wenger's most painful moment in Europe came at the end of by far his most impressive run made it doubly hard to bear.

Memorable victories over Real Madrid, Juventus and Villarreal had carried Arsenal to the final as Wenger deployed a cagey gameplan at odds with his purist principles.

Yet Wenger refused to use the same conservative strategy in future years, instead trying to take on the big guns at their own smooth-passing game despite mostly having inferior players.

Against middle-of-the-road Premier League and European teams Arsenal can still dazzle when they reach top gear, but their attacking style is an open invitation for the likes of Bayern and Barca to run riot.

Never was the disparity clearer than in this season's first leg against Bayern when Carlo Ancelotti's team enjoyed 75 percent of the possession and made full use of it.

Wenger never misses a chance to highlight his achievement in leading Arsenal into the Champions League for 19th successive seasons.

But deep down the 67-year-old knows Arsenal simply haven't been good enough to make the grade in Europe -- and increasingly the same appears to be true domestically too.

Saturday's 3-1 defeat at Liverpool left Arsenal outside the top four and an embattled Wenger with some explaining to do after leaving star man Alexis Sanchez out of his starting line-up.

- Under pressure -

"Overall, I must say they are a better team than us. We collapsed," Wenger groaned after the latest heavy Bayern loss.

Their only other Champions League semi-final appearance came in 2009 and again ended in recriminations as Manchester United, holding a slender 1-0 lead from the first leg, shattered Arsenal's optimism with two goals in the opening 11 minutes of the second leg in north London.

Losing to his old rival Alex Ferguson in such a pivotal match was a bitter pill for Wenger to swallow.

But, fatally, his stubborn streak ensured he would continue to construct his teams without the necessary steel required to snuff out the world's best attackers and, to no one's surprise, the end result was more failure when the stakes were highest.

Having won three Premier League titles and six FA Cups, Wenger can leave with his head held high whenever he calls it quits, but barring one of the all-time great escape acts on Tuesday, his struggles in Europe will always haunt him.

Source: AFP