The Azzurri won the World Cup as recently as 2006 - when they knocked Australia out along the way - and made the final of the European Championships in 2012, although their recent efforts (eliminated in the group stage of the 2010 and 2014 World Cups, and quarter-finals of the 2016 Euros) suggested that they were not the powerhouse they had been a decade ago.

The Netherlands, another great soccer nation, will also be absent from Russia. Their fall from grace has been even quicker: they were World Cup finalists in 2010 and semi-finalists in 2014 (when Australia was again one of the teams they defeated) but they did not even make the play-offs this time. They also failed to qualify for the Euros in 2016.

Then there was Argentina, containing perhaps the best player in the world, Leo Messi, along with a galaxy of top liners, who struggled to make it out of South America but managed to secure a place.

However Chile, the current Copa America champions, failed to make it even into the play-off position in the tough South American qualifying group.

All these results are not so much a wake-up call for Australia's players, who go into the decisive play-off against Honduras on Wednesday night with the memory of their extra-time win and last-minute let-off against Syria top of their minds - but any Australian fans who might be feeling complacent after the team's 0-0 draw in Honduras on Saturday morning.

The players know all too well the pitfalls that any opposition can present, and supporters should be aware that the Hondurans, while perhaps not the toughest of opponents, are a threat.

All they need is the sort of luck, probably from a defensive error or breakaway move, that the Syrians didn't enjoy when their last-minute free kick struck the post. A goal then would have made it 2-2 on the night and put the Middle Eastern nation through to the intercontinental play-off at Australia's expense.

If Honduras score, the Socceroos will have to score twice: the infamous away goals rule, burned into the psyche of a generation of Australian players and supporters after the heartbreaking loss to Iran 20 years ago, would then come into play, and a 1-1 draw would deliver the Central Americans an improbable victory.

Socceroo coach Ange Postecoglou is well aware of how vital it is to qualify to keep up the sport's momentum in this country.

"Its very important because you want to be at the biggest tournametnt at the world. For the game its always important you are there .We saw Italy miss out and you realise the impact that has.

"It doesn't mean, not qualifying, that the game somehow ceases to exist, its more about our continued growth.

"We have to be really ambitious in the way we approach international football, wanting to qualify and wanting to do well in the World Cup and all those kind of things can't happen unless you get the job done, that's our focus."

???Failure to score when they have dominated games has cost the Socceroos greatly, never more so than the 2-1 win over Thailand in Melbourne which concluded the group phase. The Socceroos had so much of the ball it was embarrassing, but they could not break down the Thai rearguard more than twice.

Concentration lapses have also put them in this position, with Ange Posteocglou's team having surrendered the lead in away games in Iraq, Thailand and Saudi Arabia.

These are all factors that provide the backdrop for Wednesday night's game.

However, the Socceroos have had a much easier journey back to Sydney than their rivals, on a charter flight, and have several key players - Mat Leckie, Robbie Kruse and Mark Milligan - ready to return, as well as others who played little or no minutes in Honduras available to start.

They are in pole position to win this game and make it four World Cups on the spin.

But for all of that it may still be a fraught occasion. The improvement in teams from the developing soccer nations in Asia, Central America and Africa has been dramatic in the past 20 years as investment in the game have helped close the gap.

There are few certainties any more. Ask Italy, Chile, the Netherlands - or even England, humbled by Iceland at the Euros last year, who failed to qualify for the 1974, 1978 and 1994 World Cups.