Companies’ offshore cash holdings are a tempting target for American tax writers, as President Obama’s proposal this week to tax deferred offshore earnings proves. Those same offshore earnings may attract foreign buyers as well.

A Bloomberg article on Wednesday by David Kocieniewski rightly identifies an unintended consequence of the president’s proposal: It provides companies with an additional incentive to hurry up and move their headquarters overseas before the rules change.

I think the more formidable concern is an increase in foreign acquisitions of companies in the United States. Unlike a corporate inversion, where a larger American company is “acquired” by a smaller foreign one, I am speaking here of acquisitions by foreign companies that are the same size or larger than their American targets.

The Treasury Department issued guidance last year that makes it more difficult for American companies to reap some of the benefits of an inversion. In particular, the guidance makes it more difficult for inverted companies to get access to deferred offshore earnings (the same deferred offshore earnings that would be the subject of a 14 percent tax under the White House proposal).

Paper inversions were a threat mainly because of the erosion of the corporate tax base. The inversions involving pharmaceutical industry companies in recent years may not have an important effect on home country jobs, according to a recent paper by Omri Marian of the University of Florida. Mergers and acquisitions by foreign companies, by contrast, pose a threat beyond just revenue effects. In these transactions, jobs follow headquarters.

Consider what Mihir A. Desai, a professor of law and finance at Harvard, refers to as the “call and response” pattern that has brought us to where we are. An inversion, technically, is a foreign company acquiring an American company. Before Congress began changing the rules in 2004, an American company could invert merely by shuffling paper around. Later rules made it necessary to add some substance to the deal. An American company had to find a foreign acquirer of 25 percent or more of its size, sometimes fattening up the foreign company or reducing its own size to fit the rules.

The hunt for suitable merger partners continues, only somewhat abated by the Treasury guidance last fall. But in response to increased regulation, the next logical move is even more substantive: a merger with a real foreign acquirer, not just a post office box in an exotic location.

Mr. Kocieniewski correctly notes that although smaller companies may continue to hunt for inversion partners, the largest companies with offshore foreign holdings, like Pfizer, Eli Lilly & Company, Microsoft, General Electric and Apple, may be too big to engage in inversion transactions.

But there is a sweet spot where companies with substantial offshore cash holdings may be tempting targets for a foreign company. And companies that are too large to invert or be acquired may be tempted to sell off divisions to foreign buyers.

The rules on inversions do not apply in a merger of equals or where the foreign company is larger than the domestic target. And so the offshore cash trapped by the Treasury’s inversion guidance is unlocked — and avoids the White House proposal – if and only if the company is acquired by a larger foreign company.

The ideal size for a target is a company that is large enough to have accumulated significant offshore cash holdings, but not so large that it’s bigger than potential buyers.

Just last year, for example, Chiquita’s planned inversion deal with the Irish banana producer Fyffes was scuttled in favor of a takeover by the Brazilian orange juice producer Grupo Cutrale and its investment partner, Safra. Chiquita had $1.7 billion in undistributed foreign earnings as of the end of 2013 — cash and investments that can now be accessed by its Brazilian owners without paying any tax in the United States.

Jobs, not just revenue, are an important part of this debate. It’s not just rhetoric. (For a contrary view, see Josh Barro’s article in the Upshot.) In terms of global competition, one of the strengths of the United States is our professional class — corporate managers, lawyers, finance professionals, accountants, researchers — and those are the jobs that tend to follow headquarters after an acquisition.