In recent years, investors have grown accustomed to strong performance by the FTSE 100 index of leading British shares.

It has repeatedly hit new highs, including so far this year.

But with war in the Middle East, elevated geopolitical concerns, and uncertainty about what international developments may end up meaning for the economy, the FTSE 100 has been heading downwards over the past couple of weeks.

Could this be a sign of worse to come?

UK listed, globally active

The FTSE 100 contains 100 shares listed on the London market. But while it has its fair share of British businesses like Next and Severn Trent, FTSE 100 companies make most of their money overseas.

That reflects the global nature of many of the firms, such as Prudential and Unilever. So, global events can certainly have an impact on the index.

For FTSE 100 companies like oil majors BP and Shell, rising oil prices could actually turn out to be good news.

For other members, though, cost inflation could eat into profits while uncertainty is a threat to customer demand. British Airways owner International Airlines Group is an example.

So it is difficult to form a clear picture of what impact recent events may have on index members’ business performance over time.

But, in general, markets dislike uncertainty. What is also clear is that the current global climate is pushing up some prices, reducing demand in some areas and leading businesses to postpone certain decision processes.

Taken together, that is bad news for the short to medium-term health of the world economy, in my view.

Here’s why I’m a long-term investor!

Fortunately, though, I take a long-term approach to investing.

So, when share prices seem attractive even for a short period of time, I have a buying opportunity. But when the price of a share I own falls below what I think is reasonable for the business, I do not lose any sleep over it.

Over time – even if it takes years – I expect that buying a diversified portfolio of high-quality companies when I can do so for an attractive price will help me to build wealth.

Looking for opportunities in today’s market

That helps explain why I am not too worried about what is happening to the FTSE 100 right now.

It could be that the strong performance of the past several years now becomes a memory and the party ends, with the index continuing to slide.

That would not bother me, though, as over the long run I expect the index to do well – and right now I am looking for individual shares to buy, not an index tracker.

One FTSE 100 share I continue to think investors should consider is JD Sports (LSE: JD), which sells for pennies.

Fragile consumer confidence could hurt demand for pricy sportswear. Higher global shipping costs is also a risk to profitability.

Still, I think the business has a lot going for it. It has a strong brand, large customer base, global footprint, and proven business model.

I reckon the current share price looks cheap from a long-term perspective, at just eight times earnings.

JD Sports has grown substantially in recent years and navigated demand and supply chain risks before. I am optimistic that it has what it takes to keep doing so.