For mid-market U.S. companies trading or operating in foreign markets, it can be tempting to treat risk assessment as a pre-transaction process undertaken primarily in advance of a major business deal or insurance renewal.

But without continuously evaluating the liability exposures associated with their overseas operations—as well as the insurance and loss control programs put in place to mitigate those exposures—mid-market companies run the risk of being blindsided by sudden regulatory, political, economic or weather-related changes abroad, experts warn.

In the past 12 months, natural catastrophes, increased regulation and enforcement, political and social revolutions, and economic turmoil have triggered significant fluctuations in property/casualty, employment and executive risk exposures for domestic companies trading internationally.

“It's all just so fluid,” said Richard Hylant, a principal of Hylant Group Inc. and president of its Toledo, Ohio, office. “What had been stable trade markets up until these last couple of years seem to be pretty unsteady at this point.”

One area of risk that experts said has become a critical focus for mid-market companies this year is that sector's exposure to supply line disruptions and breakdowns. In particular, weather-related events such as the earthquake and tsunami in Japan, flooding in Australia and Thailand, earthquakes in New Zealand—as well as tornadoes, floods and at least one hurricane in the United States—have presented significant, sudden threats to international supply chains and overseas business partners—on which experts said many small and midsize firms rely heavily but often do not plan adequately around for their possible disruption.

“Those events really have made it vital that mid-market companies, especially those that might not have a great grasp of their supply chain risk, take a second look from time to time and try to understand how that supply chain is put together,” said Kevin Holland, a Kansas City, Mo.-based assistant vp at Lockton Cos. L.L.C. Aside from securing adequate business interruption and property insurance, Mr. Holland said companies should explore contractual redundancies that can reduce loss exposures in the event a supplier goes offline.

“As more and more U.S. companies become dependent on overseas suppliers, those companies need to confirm and reconfirm that they're insuring that risk appropriately, and that they're putting in place the right process to address a shutdown of a critical operation,” Mr. Holland said.

Military coups, revolutions and uprisings, corporate nationalizations and other political risks also can manifest with little warning and wreak havoc on a mid-market company's business operations abroad, experts said. Mr. Holland pointed to the recent revolution in Libya as just the latest in a series of marketplace lessons to mid-market companies on the importance of actively monitoring events in any country that affects their operations.

“North Africa and especially Libya had only recently opened up again in terms of its receptiveness to U.S. companies,” Mr. Holland said. “We saw a flood of oil field contractors and designers going in; and then in the course of nine months, everyone's got to get out again.”

That has emphasized the need to consistently frequently monitor employee and resource placements overseas, as well as secure insurance against losses stemming from dissolved contracts with ousted regimes. “Understanding the risks that you have tied to other governments outside the U.S. becomes more and more important, considering the contract frustration you can encounter fairly easily in some of these countries,” he said.

Of course, experts said, there may not be a more erratic set of international commerce risks than those directly linked to the state of the global economy. In particular, the volatility of the European debt crisis has had a devastating effect on companies that have subsidiaries or other business relationships with ties to eurozone states, said Scott Kantrowitz, a New York-based regional manager for the ACE USA Inc.

“We're finding companies (operating internationally) unable to make to payments on contracts or invoices, which can result in bankruptcy or other financial trouble,” Mr. Kantrowitz said. “We see that as a huge issue for our clients, and are starting to see potential shareholder litigation arising from displeased foreign investors.”

However, laws stiffening penalties for bribery and increased enforcement of other rules in the United States and abroad present the greatest consistent risk for mid-market companies (see related story).

As long as economic recovery worldwide remains slow or stagnant, experts said countries are likely to continue building their regulatory footprint.

“It could be tax authorities, customs officials or any other regulatory agency,” said David Williams, the Boston-based worldwide manager of the Chubb Group of Insurance Cos.' multinational solutions group. “Certainly, authorities around the globe are seeking more revenue for their governments.”