Here are the 4 news articles with headlines:
1. **William visiting UK troops on Estonia–Russia border**: This article reports that Prince William is visiting British troops stationed on the Estonia-Russia border.
2. **Trump suggests US could run Ukraine’s power plants**: The article states that former President Trump has suggested that the US could take over the operation of Ukraine’s power plants.
3. **Starmer’s ad hoc alliance could still struggle to materialise**: This article discusses the potential challenges faced by Labour leader Keir Starmer in forming an alliance with other parties.
There are also a few additional elements:
* A BBC News newsletter promotion, encouraging readers to sign up for their Politics Essential newsletter.
* Links to related topics on the BBC website: War in Ukraine and Keir Starmer.