Nancy McLernon is the president and chief executive of the Organization for International Investment, a business association representing the U.S. subsidiaries of global companies.

Today global companies operate different divisions all over the world. Planting a country's flag on a firm is nearly impossible. Yet certain acquisitions can lead some to question the global marketplace and whether we should safeguard ourselves from it. Last week, it was the proposed acquisition of Smithfield Foods by Shuanghui International of China.

If bacon production qualifies for national review, what's next? Ketchup?

The U.S. has historically been open to foreign investment because it has helped fuel manufacturing, innovation, trade and job creation in our economy. Foreign companies employ 5.6 million Americans, write over $400 billion annually in paychecks and produce 18 percent of U.S. exports.

However, national security concerns should trump all other factors. For that, the U.S. has a robust process for reviewing foreign acquisitions that raise such concerns, like deals related to defense or critical technology. If an acquisition is found to have national security implications that cannot be fixed, then the U.S. can step in and prevent the deal from going forward. Congress carefully constructed this process to ensure the necessary balance between the protection of vital national security interests and the economic benefits of foreign investment.

If bacon production qualifies for such a review, what's next? Ketchup? Bottled water? That kind of review would divert attention from the deals truly related to national security and would send up an isolationist flare to the world.

Of course, the safety of our food supply is paramount, regardless of a company’s ownership. Our government has delegated that important job to the U.S. Department of Agriculture and the Food and Drug Administration. We should not duplicate the task with another agency that has no expertise in this area. Smithfield products will need to continue to meet all U.S. health, food and safety standards. That is the price of entry to our market.

Having the right policies in place has helped attract global companies to establish operations here, making the U.S. the world’s leader for cross border investment. Last year that meant an additional $175 billion invested here. It’s an enviable position that many other countries are aggressively working to change. Let’s make sure they are not successful.