''All politics is local.'' - The late Thomas P. ''Tip'' O'Neil, Speaker, U.S. House of Representatives

Any good businessman knows that it takes local talent to guide him through the thicket of rules, regulations and laws of a foreign country before he can do business there.It could, perhaps, be said that this basic home truth applies even more to the United States than to any other country in the world.

Globalization is a fact of life. Americans buy up companies in foreign lands and foreigners come here to buy some of our companies. In 1998, Americans invested $289 billion overseas.

For a foreign firm coming to the United States, working through the obvious course of legal and regulatory hurdles is merely the beginning. The real test comes in the form of local politics. By this is meant not just those at the federal and state level, but at the city, county and neighborhood level as well.

Horror stories abound of foreign companies that ran aground on the reefs of local politics.

Perhaps one good illustration would be the recent adventures of ScottishPower as it sought to acquire an American electric utility called Pacificorp.

The price was more than $6 billion. The resulting mega-utility would be the world's 12th largest. It would also make ScottishPower the first foreign company ever to acquire an American utility. It had the early backing of the Federal Energy Regulatory Commission (FERC) and its British counterpart.

Even so, and despite touching all the obvious legal and regulatory bases, ScottishPower was surprised by a whirlwind of unanticipated problems generated by, among others, consumer activist Ralph Nader, state legislators, a governor and an Oregon housewife, active in her local rate-payer's association.

Pacificorp operates in six Northwest states. For the deal to succeed, approval is required from the utility regulators in each state, FERC, its UK counterpart and shareholders in each company.

ScottishPower announced its takeover plans on Christmas Eve of 1998. Unanticipated problems quickly surfaced. In March, Nancy Newell, a leading figure in the North East Ratepayers Group, pronounced the deal bad for consumers because no mention was made of a decrease in prices.

She allied with Critical Mass Energy Project, a Nader group. Then Nader himself vowed to fight the takeover. Next the group secured pledges of solidarity from labor and environmental organizations groups plus several of Paciificorp's big industrial customers.

The opposition then made its case to members of the Utah and Oregon legislatures and Utah Gov. Michael Leavitt. He publicly demanded a 5 percent reduction in charges to homeowners.

Members of the Oregon and Utah legislatures began circulating draft legislation that would prevent ScottishPower from recovering more than the $3 billion premium it spent buying Pacificorp stock.

The pressure began to tell when regulatory commission staff in Oregon and the regulatory department in Utah gave only conditional approval.

There followed a long and complex series of negotiations between ScottishPower, selected members of the legislatures of Utah and Oregon, the governor of Utah and a collection of consumer groups.

In the end an agreement was reached. In Utah it called for ScottishPower to provide a credit to customers of $12 million per year for four years beginning in the year 2000. It also contains a mechanism for possible recovery of much of the cost of these reductions, but not at the expense of consumers.

Oregon consumers will also get a credit - beginning one year after the merger becomes official - of $12 million per year for three years and $15 million in the fourth year. The agreement also calls for the adoption of service standards and conservation commitments.

Dealing with the unforeseen problems is estimated to have cost Scottish power an extra $6.5 million.

''It would not be the first time the colonists have ambushed the British,'' said Roger Ball, the official advocate for utility consumers in Utah. ''The cultural barriers are enormous. I don't believe they know what they've gotten into.''

The director of the Oregon Consumers Utility Board said after meeting with executives of ScottishPower: ''I guess we were speaking the same language, but on different planets.'' A columnist in the London Observer noted: ''The American planet can be a dangerous place for British operators to land.''

As one who has spent some time in Britain dealing with business people there, I would agree.

What are our foreign friends to learn from this sort of guerilla warfare and how can they protect against it? It seems to me there are three lessons to be learned:

1.) Touching the obvious legal and regulatory bases is not enough.

2.) There will always be some non-governmental group of civic activists lurking in the bushes. One needs to find out in advance who they are and learn how to deal with them.

3.) Never underestimate the ability of the most humble of these groups to cause considerable trouble.

In the immortal words of Meredith Wilson, who wrote the Broadway musical ''The Music Man,'' ''You've gotta know the territory.''