This isn't a distraction; it's a change in strategy that was announced back in June.
Resources are being focused on preparing for direct attacks on the UK, including cyberattacks, disinformation campaigns, sea and air incursions, assassinations, deliberate disruptions of resource chains (food, energy), weaponisation of flashpoint issues (all already happening) as well as the more remote-seeming possibility of an actual land invasion, drone bombing campaign, or nuclear attack. The goal is to create not just working defenses but also deterrents and increased public awareness. Starmer also probably means to both strengthen the overall position and perception of NATO and position the UK as a NATO leader (we haven't yet arrived at the part of Project 2025 where the USA withdraws from NATO, but given what we've seen from Washington it's reasonable to expect that it's coming). This is a real shift as since the end of the "Cold War" the focus has mainly been on foreign aid, development aid, and supporting international responses abroad (Afghanistan, Iraq, UN "peacekeeping").
Is he overreacting/misdirecting? Look at what we've seen since the 2022 invasion of Ukraine: traditionally neutral countries (Sweden, Finland) joining NATO, countries far from meeting the accession criteria desperate to join (Ukraine, Moldova), Poland shifting resources massively to prioritise rapid large-scale military growth, Germany accelerating its post-"Cold War" switch back to an aggressive military policy, Lithuania taking Belarus to the ICJ for weaponising migration, Hungary accepting a one million Euro fine per day as the price of protecting its borders, the USA weaponising tariffs to influence not just "bad actors" but anyone who does business with them. And most recently, Putin's high-profile charm offensive in Shanghai with unlikely co-stars Xi, Modi, and Kim. It's natural to be cautious or even anxious about the UK's shift, but I don't think anyone really feels that the previous strategy was adequate.
As for people who won't lift a finger to defend the UK - fair enough, but again, look at eastern Ukraine. People there may indeed be fighting for their country and flag and identity but even without those, they'd be fighting to stay alive and protect their families.