A family friend recently told me the story of her parents, who migrated from Greece to Australia in the 1950s. They settled in rural South Australia, where her father earned his living as a fisherman. A huge storm hit and he went missing for three days. When he finally returned safely, his wife was overjoyed – but the stress of the event did not leave her. In broken English, she consulted the local doctor and asked him about how to settle her nerves. In an age of innocence, he advised her to take up smoking. She died of lung cancer.

Al Gore, who self-effacingly told us in his movie, An Inconvenient Truth, that he was the man who "used to be the next president of the United States", recalled a similar story. He and his older sister worked summers on the family’s tobacco farm. She took up smoking as a teenager and died of lung cancer. "My father, he had grown tobacco all his life. He stopped it," Gore said. "Whatever explanation that seemed to make sense in the past just didn’t cut it anymore."

Australia’s health minister and then attorney general Nicola Roxon introduced plain packaging of cigarettes and then went on to fight an epic legal battle against big tobacco. She won in August 2012. The tears cried were of joy, mingled with relief.

Since 1 December 2012, cigarettes packets in Australia do not sparkle with gold or silver and do not have any other way to catch and please the eye. They're a uniform drab colour, with most of the box taken up with the most graphic health warnings. Gruesome pictures of disease perhaps better described as real pictures of the ugly truth.

Australian plain packaging for cigarettes. Photograph: PA Photograph: PA

Evidence is already available: plain packaging works. Smokers are more likely to consider giving up, and they're also more likely to think the quality of their cigarettes has diminished. Research also shows that when young people look at plain cigarette packs, they believe the product is used by people who are less stylish and sociable, and not as attractive to mimic. This helps break the cycle of attracting young "replacement" smokers progressively taking the place of those older smokers who have quit or, too often, died.

On 11 January 2014, it will be 50 years since the US surgeon general told the world that: "cigarette smoking contributes substantially to mortality from certain specific diseases and to the overall death rate." Since that warning first reverberated around the world, tobacco use has dropped staggeringly in developed countries. Policies to increase price, prohibit access by young people and deter smoking in public places, combined with public education, have had a dramatic affect.

Policies to reduce the glitz of smoking have made a contribution too. In Australia, you can no longer watch elite sport sponsored by big tobacco and somehow take away the message that smoking and extreme athleticism go hand in hand. You can no longer grow up watching cigarette advertisements on television telling you that you're successful and sexy because you puff. No one tells you to "join the club", that "only the best will do", or "anyhow to have" a cigarette.

But a nation of 23m people still sees 15,000 people die a year because of tobacco. The fight has not been won yet. Plain packaging is the logical next step in this campaign to kill the glamour and substitute it with the facts: smoking equals death.

In the face of 50 years of truth and action, big tobacco has engaged in 50 years of denial and resistance. Political donations have been made to try and buy damage limitation. Death rates in the developed world have come down but they have gone up in the developing world, where new markets have been sought.

A weapon in this war is trade policy. Legitimately, the world takes a dim view of trade restrictions that masquerade as something else. The world also needs to take a dim view of trade manoeuvres that are really about protecting the remaining ground for big tobacco.

Tactic one is to harry nations that step up to the plate and do something new. Australia is entangled in five World Trade Organisation (WTO) disputes about plain packaging. One of the nations challenging Australia's tobacco law is Ukraine, which has not exported tobacco to Australia since at least 2005. Legitimate trade policy objections, or big tobacco at work? You decide. But in deciding, you should know British American Tobacco has confirmed it is assisting with the costs incurred by Ukraine.

The cost burden for Australia in dealing with these disputes will be measured in the millions of dollars, but another impact of this conduct is that other governments contemplating adopting plain packaging policies are waiting and watching. Earlier this month, New Zealand announced that it would legislate for plain packaging in 2014. However, it is also keeping a wary eye on the WTO proceedings, having caveated its original announcement of its intention to proceed on the 19 February 2013 on the basis it would not do so until legal cases against Australia were resolved.

Tactic two is to ensure new trade agreements give a right to tobacco companies to keep contesting domestic policies. For the US, the Trans Pacific Partnership is its biggest strategic trade play. President Obama has personally invested in bringing to life a free trade agreement for 12 countries in the Asia-Pacific region, including Australia. China is not a participant in the TPP negotiations.

The first position from the US about tobacco was advocacy of a carve-out that would quash legal challenges against tough tobacco laws, meaning there could be no trade dispute based on the adoption of domestic laws that hit tobacco products as long as those laws did not discriminate on the basis of the country of origin of the tobacco, and that the approach was scientifically based.

In August 2013, the US position became that tobacco should be covered in the TPP by the general exception for matters necessary to protect life and health. A challenge could be taken to another country’s anti-tobacco laws but if that happened, the health authorities must hold discussions first. The change came after consultation with Congress and other stakeholders. The Obama administration maintains that the two elements of this new approach will "work together to preserve the right to regulate tobacco products domestically". Others have their doubts, and Malaysia has countered with a call that tobacco be excluded entirely from the negotiations.

The carve-out matters, as does the question of the inclusion of investor-state dispute settlement provisions. Such provisions give companies a new place to take disputes – a tribunal that stands separate from and above domestic legal systems. Philip Morris, having lost in Australia’s high court, is using such a provision in an Australia-Hong Kong investment treaty signed in the early 1990s to keep contesting plain packaging.

Negotiations for the TPP are still ongoing. Like all trade deals, negotiators only empty their pockets and get the deal done if the push from national leaders is hard enough. But as negotiators tussle, in this trade deal and in every other, the sharpest of eyes need to be on the lookout for the stealthy influence of big tobacco.

Free trade equals more jobs and prosperity. Less smoking equals more people alive and healthy. Both can be achieved.