‘While there’s no substitute for congressional action, my administration will act wherever we can to protect the progress the American people have worked so hard to bring about.” With this nonsensical statement, President Obama brought about an easy change to the tax code, as substitute for congressional action, that doesn’t represent any progress at all.

Treasury Secretary Jack Lew announced last night that the IRS will change its rules for “tax inversions,” deals in which American corporations acquire or merge with foreign businesses for tax purposes. The new rules won’t make such deals illegal, but they will make them less profitable, or harder to profit from.

The Treasury Department has a good deal of leeway in how it interprets the ambiguities of tax law, but this decision is clearly a political usurpation. The IRS justification says that inversions may be eroding the tax base, but that’s only true in the most marginal way. The deals have attracted a great deal more political controversy than they have ever mattered in terms of federal revenue.

The rule changes will apply only to mergers and acquisitions that occur in the future. This is still disruptive, since some corporations (the infamous Burger King included) have been working on such deals in light of the existing tax code for some time. Congressional Democrats, though, had an even worse idea, demanding an ex post facto change that would raise taxes on deals corporations have been doing since the 1990s.

There’s only one way to make American companies stop fleeing the tax code: Create a tax code they don’t want to flee. Some Democrats admit that fundamental tax reform is necessary — even President Obama has a plan — but say that staunching the flow of inversions is a pressing concern. It isn’t, and it reinforces the undesirable aspects of our tax code. American companies shouldn’t have to pay U.S. taxes on overseas earnings — the driving concern in the Burger King deal — and shouldn’t have to deal with the highest statutory corporate tax rate in the world.

But corporate tax reform is also about much more than undoing the exceptional aspects of the American tax code — it should also be focused on encouraging investment and wage growth. California Republican representative Devin Nunes, for instance, has proposed taxing business cash flow rather than profits, which would make business investment easier and cheaper.

The politics of IRS decrees about inversions are simple; the politics of tax reform are complicated. But the benefits to the former are vanishing, while the benefits to the latter are real.