The time-worn Sun Tzu axiom may as well have been tattooed on Thomas Mulcair's right hand as he arrived Monday for his first day on Parliament Hill as the leader of the official Opposition.
With his sworn political enemy, Stephen Harper, on the other side of the globe in South Korea, the new NDP leader had no one to truly fight with.
After striving diligently in the last few months during his party's leadership race to shed his thin, combative skin in favour of a thicker, more collegial veneer, Mulcair wasn't about to let it all unravel. Not even when a Tory backbencher essentially recited the script of what will likely be the Conservative attack ad on Mulcair.
Ontario MP Jeff Watson used his pre-question period statement to inform the House of Commons that the NDP chose a new leader "who will continue to push its high tax, high spending, job-killing agenda."
Watson declared that Mulcair would bring back a "a risky job-killing carbon tax" and would engage in "dangerous economic experiments."
Watson called Mulcair a "hug-a-thug, soft on crime leader" with "a divisive personality" and "ruthless ambition."
Mulcair shrugged it off. After making his question period debut to a standing ovation from his caucus and compliments from his defeated opponents, Mulcair attacked the Conservative government's economic record.
He said the government has failed miserably at getting the country back to work and demanded action in Thursday's budget.
"Since the Conservatives came to power, Canada has lost hundreds of thousands of good jobs in the manufacturing sector," Mulcair said.
Heritage Minister James Moore retorted that 600,000 jobs have been created under the Tory watch.
"We will continue to move in that direction in the next budget," Moore said.
Mulcair wasn't buying that.
"They are leaving the largest environmental, economic and social debt in our history for future generations," he said.
"They are emptying the manufacturing sector and destabilizing the balanced economy that had been created since the Second World War."
Outside the Commons afterwards, Mulcair insisted he will continue to take the high road — for now.
"They're very good at defining their adversaries," Mulcair said. "We're going to start to define them."
He said voters will develop a clearer idea of what the NDP stands for in the coming years, as the party eyes the next federal election in 2015.
Until then, he said, the NDP will call the government to account, and oppose, "but more and more, you're going to hear us propose."
Harper may not have been in town, but the tone his party has set in recent years — strict message control combined with scathing attacks on its political opponents with deep-pocketed advertising campaigns —seemed to resonate with Mulcair and his team.
That much of Mulcair's day unfolded outside of the public eye — just like so many of Harper's — should have come as no surprise. As Mulcair himself said on Sunday at his first press conference after winning the leadership, his party faces "a government that's very tough, very well structured, and we've got to do the same thing."
So Mulcair absorbed some of Harper's command and control ethos.
Mulcair made a show of moving to his new Centre Block office. The event came directly from the Conservative's play book — it was for cameras only, no questions.
The staged event had some of the awkwardness of Harper's early photo-ops. Mulcair kissed his wife's forehead and then he sat in his chair. Hands clasped, he smiled for the cameras briefly before pretending to sign some papers on his desk.
Behind closed doors earlier that morning, Mulcair's traditional hard-edged persona emerged when he met with representatives of the workers of Aveos, the Air Canada maintenance subcontractor whose 2,600 workers were laid off last week.
Marcel St-Jean, the president of the International Association of Machinists and Aerospace Workers, said Mulcair looked well prepared, and pledged to ask good questions on their behalf. Mulcair, he added, has been a strong supporter of his workers, and has in the past attended several rallies in support of them.
"He said he's going to be with us 100 per cent," said St-Jean.
"He looks pretty combative. ... The impression that I have is he's a man ready to get to work for Canadians. He looks pretty ready. He's got a good dossier, and he's prepared to work."
Later in the House, Mulcair made good on his promise, pressing the government on the Aveos workers on his third and final question.
"Let us talk about how Canadians are going to live their lives when thousands of families are about to lose their livelihood with the shutdown of Aveos. These jobs are about to exported," Mulcair said, calling on the government to invoke legislation that would protect the jobs.
Mulcair's main rival, senior party strategist Brian Topp, released a statement Monday calling for support of the new leader.
"When it's over, it's over. And like all New Democrats all across Canada, there must be only one thing on all of our minds from now on — unity behind our new leader, Tom Mulcair; strength; and an absolute focus on the task at hand, which is to offer Canadians a better government."
Mulcair's four caucus opponents also spoke of the need for unity as the party moves forward.
Toronto MP Peggy Nash urged the party to "unite behind our leader and future prime minister."
In the end, it was an unexpected tribute by Olivia Chow, widow of former leader Jack Layton, that nearly shattered Mulcair's controlled demeanour.
Chow had remained pointedly neutral during the campaign, but she unleashed her own enthusiastic tribute to Mulcair.
"We can be proud to say that New Democrats across Canada elected a strong and experienced leader to lead Canada's New Democrats to form the next government in 2015," Chow told the Commons.
"I am proud to have a leader who worked alongside Jack Layton to unite Quebecers and Canadians together, a leader who shares our values ... a leader who will hold the Conservatives to account and fight for everyday Canadians."
The New Democrats rose to their feet cheering once more, while Mulcair strained forward to meet Chow's gaze down the line of the front bench. His face was bright red, and he appeared to be choking back tears.
And then the new leader sat back, breathed deeply, and looked across the aisle at Harper's empty seat.
CORRECTION: An earlier version of this story had an incorrect nationality for the Chinese military general Sun Tzu.
Also on HuffPost