LONDON — Political leaders nowadays are fond of talking about national identity and culture, but do we know what they mean by either identity or culture, and do they know themselves what they mean?

A prominent British Labour Party leader, Jack Straw, the former foreign minister — and quite likely to be become foreign minister again soon — has been telling the British people that they should think more about their identity and have a clearer idea of what it is to be British. He urges teachers to teach in schools about Britain’s “long struggle for freedom,” and argues that while the country’s numerous different ethnic groups and minorities should be allowed their separate cultures, this should not override their Britishness.

So there we have it — “identity,” “culture,” “freedom” — these are big words that get thrown about, and words are very powerful. But those who use them need to do so with great care. Identity gets much talked about nowadays because globalization and the total international pooling of information via the worldwide Web seem to dissolve national identities and leave people wondering where they belong and where their roots lie.

Much of the best “glue” to tie people together in any nation is a good knowledge of that nation’s, and society’s history, both the good bits and the bad bits. Yet who were the people who rubbished history in Britain, and marginalized it in school syllabuses? Why, the selfsame Labour Party leaders, including Straw, who now bemoan the lack of Britishness and want children reminded of their history again.

But this time they seem to want a somewhat different version. Instead of the old sort of British history, which told youngsters all about their nation’s battles and victories, about its place in the world, its conquests and defeats, they want the emphasis to be on “freedoms,” which means on the overthrow of feudalism and absolute monarchy, the securing of individual rights and religious toleration and the arrival of democracy (which only came late to Britain — 1922 when half the population, its women, finally got the vote).

Nothing wrong with that, except that it leaves out half the story — the more important half. The key answer to the questions “Who are we” lies in understanding how a nation or society has evolved, how it fits into the rest of the world, where it stands and what its national purposes and values are.

Being British only becomes a credible concept in relation to being foreign. It is a nation’s foreign and international policy and the whole history of its relationship with its neighbors that define it and tell its population where they stand in the world. This is a fact that applies especially to island nations with stormy pasts — such as Britain and Japan. In the British case, however, all this is now far from clear.

One moment the British are told to forget Britishness and be good Europeans. The next moment we are America’s closest friend and ally. And the next we are warned that Britain is no longer really a nation at all but a polyglot collection of cultures and races. Moreover, it is a kingdom that is about to become less united if Scotland goes its independent way — the Federal Kingdom rather than the United Kingdom.

Nor is the meaning of “culture” much clearer. “Culture” means the laws, customs, traditions, values literature and history of a group, tribe or nation. If every grouping in a nation is encouraged to live inside its own cultural shell — the multicultural theory — the result is fragmentation and separatism — a clear departure from unifying national identity and loyalty.

For example, Islamic groups in Britain want to live under their own Shariah law. Is this consistent with Britishness? Nobody knows, and airy generalizations from political leaders merely confuse the matter.

So how much of their “own culture” are ethnic minorities to be allowed? And how much freedom do people feel they have in a society that is now dominated by public authorities and regulations and controls and surveillance. (A recent survey uncovered that officials now have more than 250 laws allowing them to walk uninvited into people’s private dwellings).

The inconvenient truth is that these words are meaningless unless much more carefully defined, and Britishness is meaningless when its leaders cannot even decide where Britain belongs. Politicians who use them betray a deep ignorance of how the world works and of human nature and human hopes and aspirations.

This is an age when more and more people round the globe worry about their identity and their roots. Genealogists, archivists and librarians report an unprecedented public interest in family trees and origins.

The best unifying and reassuring message for any nation or society is to insist on honest, frank, unbiased and full teaching in schools of all history — in unvarnished form — and to insist as well on primacy of national laws and norms, with tolerance of local customs within limits.

Taking a nation’s history away and then trying to put it back in doctored form is deeply misguided and fruitless. Only when most people know who they are and how their past has shaped them is the society or nation within which they live going to be comfortable and at ease with itself. That is a lesson that many political leaders have yet to learn.