The U.S. Congress has finally ratified the Korea-United States free trade agreement, demonstrating America’s commitment to upgrading and expanding the long-standing military alliance between the two countries to encompass the economic dimension.

With Washington completing its part of the deal, the ball is now in Korea’s court. The ruling Grand National Party is cranking up efforts to pass the KORUS FTA bill within this month, a deadline that needs to be met to ensure that the pact takes effect in January as scheduled.

But the ruling party is facing stiff resistance from opposition parties, which have been demanding re-renegotiations with Washington on the grounds that the renegotiations undertaken last year at the insistence of the United States broke the balance of interests in the original agreement in 2007.

But opposition parties have to realize that the train has already left the station, so to speak. With the U.S. Congress’ ratification of the trade deal, another round of negotiations has simply become impossible. For Korea, the choice is therefore between endorsing the modified version and rejecting it altogether.

Given the tremendous significance the trade agreement carries for both countries, rejecting it is simply out of the question. Opposition parties do not want to go that far either. Hence the only option left for them is to cooperate with the ruling party to make sure that measures for vulnerable sectors are in place before the pact goes into effect.

Unlike the U.S. Congress, which completed the whole ratification process within a week, the Korean National Assembly needs much more time to put the FTA into effect. After passing the ratification bill, lawmakers need to follow it up by revising the 14 related acts, on top of the nine that have already been amended.

Yet the FTA bill has not even cleared the Assembly’s Foreign Affairs, Trade and Unification Committee. Rep. Nam Kyung-pil of the GNP, who chairs the committee, said his party would have the bill clear the committee by Oct. 18 and the plenary session on Oct. 28. He further said the demands put forward by the main opposition Democratic Party were negotiable. The ruling party should embrace the opposition camp’s demands as much as possible.

The DP has put forward what it calls a “10+2” proposal, which calls for rectifying 10 items in the modified pact through re-renegotiations with Washington and adding two more measures aimed at minimizing the deal’s negative effect on local industries.

We appreciate the DP’s efforts to protect the interests of the nation as well as the sectors that would be adversely affected. But now it should withdraw some of its unrealistic demands and instead focus on measures that are within the administration’s reach.

Opposition parties need to heed the strong bipartisan support for the free trade agreement in the U.S. Congress, which is an unmistakable sign of American willingness to open a new chapter in the Korea-U.S. alliance.

President Lee Myung-bak described the free trade deal as signaling the beginning of an “economic alliance” between Seoul and Washington. He stressed it would strengthen and broaden the strategic alliance between the two nations beyond the military and security realms.

The KORUS FTA is also the best answer to the global economic crisis. It will help the two countries expand trade, stimulate investment, create more jobs and keep their economies growing.

According to economic research institutes, the trade deal would provide a new growth engine for Korea. It is expected to help the nation create 350,000 new jobs over the next 10 years, boost GDP by 5.6 percent during the period and push up its trade surplus with the United States.

Given all these and other benefits, it is imperative for the ruling and opposition parties to ensure that the trade pact goes into effect without further delay. For its part, the government should fully cooperate with the political parties to minimize damage to farmers and other vulnerable sectors.