Michael Clarke led the Australian team that crushed England 5-0 on home soil in 2013-14, his side's uncompromising attitude spearheaded by Mitchell Johnson and no better summed up than by the verbal barrage towards Anderson in the first Test at the Gabba that resulted in the captain being docked 20 per cent of his match fee by the International Cricket Council.

Four years on and Clarke believes Smith's team has an opportunity to establish its own identity when the series begins in Brisbane on Thursday.

Warner has already made clear his world view when it comes to the Ashes, saying last month that "as soon as you step on that line it's war" and predicting words would be exchanged from the outset.

With so much on the line, Smith's direct predecessor says it is up to the captain to decide whether that is the approach that can be most successful for his team.

"[Warner] has made it pretty clear how he wants the team to play this summer," said Clarke, who will commentate on the series for Channel Nine. "Whether Steve Smith agrees with that or not is going to be an interesting conversation in that change room.

"Davey has come out publicly and said, 'No, we've got to show more aggression, we've got to go hard and I want it to be like war on the field'. I've always been a big believer that it's not so much what you say, it's what you do. But body language and intent is so important. If Smithy doesn't want the team to play like that, then that's going to be interesting."

Australia enter the Ashes as $1.40 favourites to win back the Ashes with Joe Root's England priced at $4. After losing 2-1 at home to South Africa last summer there is a great deal riding on the outcome of this series.

"Australia is ranked fifth in the world. If we lose this series ... there's going to be pressure on a few people," Clarke said. "This is their chance to not only win the Ashes but to turn that around. We're accustomed to Australia being the best team in the world and I'm certain that's where Steve Smith wants his team to go and that's why I see it as a wonderful opportunity for this Australian team.

"Are they going to go that aggressive approach like we did four years ago and use Mitchell Johnson in short spells and not care about his accuracy? We spoke openly with our bowlers that our attitude was going to be from seven to eleven we weren't bowling blokes out. We were getting them caught off the glove, caught at bat pad, caught at third-man. We had a really set plan that we felt was going to win us the series.

"I think the Australian team is a little unsure about their style at the moment probably because they've had so many changes in different formats of the game. How does Steve Smith want the Australian team to go about their work? How does he believe this team can get back to No.1 in the world?"

Whether Warner is re-installed in an attack-dog capacity for Australia is unclear but Clarke is unequivocal about the importance of the vice-captain to the hosts' chances. He is adamant he needs to be as close to the action as possible and said he had been frustrated to see Warner fielding at mid-off and mid-on or "putting his hand up to go field at fine-leg".

"I think his attitude is the key to Australia's intent," he said. "When he walks out and bats with that intent he always has success. To me he needs to be involved in the game all the time.

"He needs to set that tone because it's in his character. He actually plays his best when he is aggressive with his approach, both in the field and even verbally at times, but then the way he bats as well."