One year ago Friday, President Obama signed a free trade agreement with South Korea, a step that marked his arrival as an unexpectedly aggressive trade supporter. And on the agreement's first birthday, the opponents of the largest trade deal to be enacted in years haven't put their knives away.

In short, the argument that Global Trade Watch, the United Steelworkers, and other advocates are making: Imports from South Korea are up. U.S. exports to the emerging industrial giant….not so much.

Trade with South Korea isn't all champagne toasts. Here, President Obama and South Korean President Lee Myung-bak at a state dinner in 2011. (Charles Dharapak - AP)

“The actual outcomes…are exactly the opposite of what the Obama administration promised,” says a news release from Public Citizen. They note that the U.S. trade deficit with South Korea is larger than the year before, with goods exports to South Korea dropping from $43.4 billion in 2011 to $42.3 billion in 2012, and imports from South Korea climbing from $56.6 billion to $58.8 billion.

The leading defender in the public square, the office of the U.S. Trade Representative, notes a 1.3 percent bump in the sale of manufactured goods, and an 8.7 percent increase in services. There will be many more American law firms, apparently, hanging a shingle in Seoul because of the FTA.

So should we praise the South Korea free trade agreement or bury it?

Both sides are picking their facts and skirting some broader questions. The increase USTR cites in manufactured exports to South Korea lagged U.S. export growth overall, for example, and did not keep pace even with underlying economic growth either here or in South Korea.

The administration likes to cite the number of jobs generated by exports, which they put at roughly 5,000 for each $1 billion. But all exports are not created equal.

There’s an extra $1 billion of wheat and soybean exports embedded in the trade numbers, for example. But do we think there’s actually an additional five thousand people working in America’s farms and fields or affiliated industries because of that? And if goods exports have dropped $1 billion, does that mean there are five thousand fewer people producing goods as a result? Or have they all gotten jobs as lawyers and hooked up with the firms expanding abroad?

Neither of those conclusions is true, but a literal reading of pro- and anti-trade literature can lead down some confusing byways.

Just as the administration likes to focus only on the export side of the equation, trade skeptics try to amplify the significance of any rise in imports. Macroeconomic forecasters do mark imports as a drag on gross domestic product. Things the United States buys from overseas are by definition things that are not produced by a worker here.

But those same forecasters and analysts are also trying to better understand how the flow of goods and services interact, and how value gets added to products that are increasingly the end result of processes spread across countries. The United States doesn’t just import finished goods made wholly overseas. There’s a lot of other stuff in the mix – parts or materials that American companies need to finish goods that may be re-exported; finished goods that began life in a U.S. shop then got shipped overseas for final assembly.

Pick any variation on the theme. The point being that a dollar’s worth of imports does not necessarily take a dollar’s worth of production away from a U.S. company, just as a dollar’s worth of exports does not necessarily mean a full dollar of extra work.

Then there are the larger questions often lost in the shuffle. Whatever effect the North American Free Trade Agreement, for example, has had on jobs in the United States, how much value should be attached – in additional security, say, or even from a moral standpoint -- to having Mexico become middle class? Are we better or worse off with a poor neighbor to the south, or one that is growing and more secure? On a global scale, China’s rise has reshaped manufacturing. But what’s the counterfactual? China-as-North Korea – with 1.6 billion often hungry people contained by an isolationist nuclear power? Does that world look more or less promising than this one?