I’ve got cash in my Self-Invested Personal Pension (SIPP) and I’m keen to use it to buy UK shares. As the FTSE 100 dips due to the tragic war in Iran, I can see buying opportunities popping up everywhere. The question is whether now’s the moment to snap them up.

Barclays is near the top of my shopping list. I’ve wanted to add another bank to my portfolio for some time and the recent sell-off looks tempting. Barclays shares are down about 15% in a month and trade on a price-to-earnings (P/E) ratio of roughly nine.

Or should I buy Babcock International Group? The defence engineer’s shares have surged since Russia invaded Ukraine and are climbing still. The P/E now tops 27 though, so much of today’s geopolitical uncertainty is already priced in. I already have a sizeable holding in weapons maker BAE Systems but Babcock could complement it nicely.

FTSE 100 bargains

Oil & gas is another sector that’s booming today, with crude climbing above $100 a barrel and analysts suggesting it could even hit $200. I already hold BP, which has jumped about 16% in the last month, partially offsetting losses elsewhere in my portfolio. It could go higher still. Alternatively, I could balance that position by buying rival Shell. It’s the better managed company, although BP may have greater recovery potential. Today, BP yields around 4.6% while Shell offers 3.2%.

Diageo’s even cheaper

Another option is topping up my holding in Diageo (LSE: DGE), which has fallen another 20% in the last month after several difficult years.

The drinks giant has struggled since issuing a profit warning in 2023 after a sharp slowdown in its Latin America and Caribbean division. Sales have since weakened in other key markets such as the US and China, as cash-strapped drinkers trade down to cheaper brands rather than the premium spirits Diageo has focused on.

US tariffs, the threat from weight loss drugs and changing drinking habits among younger consumers also threaten sales. The death of long-time chief executive Ivan Menezes also rocked the business, while successor Debra Crew’s tenure was truncated.

I had hoped new chief executive Dave Lewis, who turned around Tesco, might spark a recovery. So far his most decisive move has been to cut the dividend by 40%, which sent the shares into another spiral. I still think Lewis will get Diageo back on track, and it’s worth considering with a long-term view.

These have all crashed

Barratt Redrow, easyJet and Melrose Industries have all tumbled roughly 25% in the last month. That could tempt investors who enjoy picking up beaten-down shares and have the patience to wait for a recovery.

It feels like a brilliant moment to go shopping for quality UK stocks. The only problem is they could still fall further.

Dan Alamariu, chief geopolitical strategist at Alpine Macro, says the war may have weeks to run and markets haven’t yet hit the “maximum panic” moment. He may be right. But catching the exact bottom of a market is almost impossible. At some point investors simply have to start buying.

My plan is to begin drip-feeding money into the market. If that panic moment arrives, I’ll accelerate my purchases.