IT TOOK HALF a decade, but bipartisan majorities in the House and Senate have finally approved free-trade agreements between the United States and three key nations: South Korea, Colombia and Panama. This is cause for celebration — but also for reflection.

First, the celebration: South Korea is a stable democracy in Northeast Asia and a growing, trillion-dollar market. Under the new deal, 95 percent of industrial and consumer goods will soon move tariff-free between the United States and South Korea, adding $12 billion annually to U.S. exports — and fortifying an alliance that helps maintain peace and security in China’s neighborhood.

The main change under the Colombia pact is to let U.S. goods enter the Andean nation tariff-free, since existing law already gave Colombia periodically renewable free access to U.S. markets. And making the mutual free flow permanent rewards and bolsters a democratic partner that has stood with the United States against drugs, terrorism and Venezuela’s Hugo Chavez. Free trade with Colombia and Panama, added to existing free trade with Chile, Peru, Mexico and Central America, creates a near-seamless partnership from Tierra del Fuego to Tijuana.

And now for the regrets: It is a sad comment on U.S. politics that it took so long to finalize agreements so manifestly favorable to this nation and its friends around the world. All three deals were negotiated by President George W. Bush and ready for Congress by 2007. Lawmakers could have acted on them while taking the public’s concerns into account. Alas, Democrats, newly in control of the House after the 2006 elections, said no — largely in deference to the labor movement’s reflexive suspicion of trade agreements. Barack Obama waffled on trade in his 2008 campaign and the early days of his presidency — until finally backing the deals in 2010.

His administration says the hesi­ta­tion obliged South Korea, Colombia and Panama to meet U.S. concerns on access to the Korean car market and labor rights in Colombia. Mostly, though, the changes were face-saving tweaks, not worth the wait.

For example, Colombia accepted a new program to stop violence against trade unionists in that country. The reality, grossly distorted by protectionists in Congress and some nongovernmental human rights groups, was that Colombia had already made vast progress against terrorism and violence. Unionists were no likelier to be murdered than anyone else. In this regard, it’s especially disappointing that, even after Colombia met Mr. Obama halfway, Maryland’s Democratic senators, Barbara Mikulski and Benjamin Cardin, still voted no — unlike Virginia’s Democratic senators and four Democratic House members from the Maryland and Virginia suburbs.

Dealing with the trumped-up labor-rights issue added months to the Colombia process. And then Republicans, back in charge of the House, upped the ante earlier this year by attacking a long-standing aid program for trade-affected U.S. workers, adding more delay.

Finally, though, negotiators from both sides smoothed over the politics. All things considered, it’s a welcome sign that Washington can, sometimes, get something done. So, go ahead: Declare the glass half full and raise it to the long-overdue victory for free trade.