The benefits of the Trans-Pacific Partnership — for which a broad agreement was finally clinched this week by 12 Pacific Rim countries, including Japan and the United States — should not be overblown. Rather, a sober assessment is needed of what Japan stands to gain or lose from a pact that, once in effect, eliminates or cuts import tariffs and sets common rules on a broad range of areas, such as investment and handling of intellectual property among countries that together account for nearly 40 percent of the global economy.

The conclusion of the TPP negotiations, which had been marred by lingering disagreements among the participants that repeatedly threatened to cast the talks adrift, may come as a political victory for Prime Minister Shinzo Abe, who not only positioned the free trade pact as a major component of his strategy to fuel Japanese economic growth but viewed it as a key to solidifying relations with Washington — along with beefing up the security alliance with the U.S. — in the face of China’s growing presence in both the economic and regional security landscape.

But the Abe administration still needs to explain details of the TPP deal and its impact on Japan’s economy and people’s lives — to the public and the Diet when seeking its ratification — a job that will be particularly important since much of the negotiations were shrouded in secrecy.

Abe’s Liberal Democratic Party was initially opposed when the government led by the Democratic Party of Japan began talks with other countries in 2011 on participating in the TPP negotiations. When the LDP returned to power, the Abe administration made a U-turn and had Japan formally join the negotiations with the 11 other nations in July 2013. At that time, the government estimated that a TPP deal would push Japan’s gross domestic product higher by some ¥3.2 trillion over roughly 10 years — an anticipated ¥2.9 trillion reduction in domestic farm and dairy output due to the influx of greater imports under tariff cuts more than offset by ¥6.1 trillion in benefits from increased Japanese exports and gains for consumers in cheaper imports.

With the broad agreement now reached, it remains to be seen whether such estimates still hold up. The accord will remove tariffs on 99.9 percent of Japanese exports in industrial products to the 11 other countries. On automobile trade, one of the key areas of the negotiations, U.S. tariffs on 81 percent of Japanese auto parts exports (in value terms) will be eliminated once the accord takes effect. However, the 2.5 percent levy on vehicle exports to the U.S. will be phased out over a period of 25 years, with the reduction to start only in the 15th year of the accord.

The hope that the tariff cuts will significantly expand Japan’s exports might need to be taken with a grain of salt, given the changes in the nation’s trade and industry structures in recent years. Many Japanese manufactures have shifted their production offshore to markets with growing demand, and the steep fall of the yen against the dollar since Abe took office in 2012 — which supposedly makes Japanese exports cheaper and more competitive overseas — has not boosted export volume as much as expected.

Meanwhile, the concessions that Japan made in agricultural trade will likely benefit consumers by lowering the price of food imports, but domestic farmers will inevitably be exposed to tougher competition. When Japan joined the TPP talks, the government said it would seek exceptional treatment for five “sanctuary” farm trade areas — rice, pork and beef, wheat, dairy products and foodstuffs for the manufacturing of sugar. Abe said his administration kept that commitment in the deal. Still, the agreement calls for sharp cuts to tariffs on beef and pork imports and creates a new tariff-free quota for rice imports from the U.S. and Australia.

Japan will, of course, benefit from becoming party to a pact that sets common rules for 21 fields ranging from finance to intellectual property, public works projects, investments, and settlement of disputes between foreign investors and governments. But what specific gains the nation will get from the deal is another question.

Often emphasized here in the process of the TPP talks has been the significance of Japan joining the U.S. in taking the lead in crafting the rules of international trade in the Asia-Pacific region, where China exerts growing influence. Japan and the U.S., which together account for 80 percent of the combined GDP of the 12 TPP partners, remain wary of China’s pursuit of a greater sphere of influence in the international economy and both have stayed out of the China-led initiative to create the Asian Infrastructure Investment Bank.

“We can’t let countries like China write the rules of the global economy,” President Barack Obama said in a statement after the TPP deal was struck. Abe also chimed in: “The TPP has been created by countries that share a basic sense of values, namely liberal democracy, basic human rights and the rule of law. It will create a free, fair and open international economic system and predominantly strengthen rule of law in the economy.”

For the Abe administration, a TPP deal was also crucial for deepening the alliance with the U.S., along with the security legislation enacted last month that paves the way for closer defense cooperation between the two countries. Akira Amari, the minister of economy revitalization who took charge of the TPP negotiations, emphasized the significance of the trade deal to keep the U.S. pegged to East Asia so that its continued presence will prevent China’s military buildup from destabilizing the region.

The TPP deal may indeed have such diplomatic and security implications. Still, this should not cloud the assessment of what Japan will gain and lose economically.

Japan has pending free trade negotiations with other countries and regions, including the European Union, China and South Korea. Abe expressed hopes that the TPP deal will provide impetus for an early conclusion of the free trade talks with the EU. But the free trade talks with China and South Korea — Japan’s largest and third-largest trading partners, respectively — have made little headway as Japan gave priority to the TPP negotiations and overall relations were severely strained by other issues. Now that a TPP deal has been struck, Japan should spend more energy on other FTA talks.

The government meanwhile plans to compile a package of measures to support the domestic farm sectors that will be affected by the TPP deal, before it submits the accord to the Diet for ratification. The LDP may be concerned about possible repercussions on farm votes in the Upper House election next summer.

When Japan concluded the Uruguay Round of international free trade talks in 1994, in which it accepted rice imports through a minimum access scheme for the first time, the government compiled a ¥6 trillion package of measures to raise the productivity of the farm sector, but much of the spending is believed to been wasted. The new measures to be taken must facilitate structural reforms of the agricultural sector and make domestic farmers more competitive — which is supposed to be a goal of the TPP deal itself.