The G20 meeting provides another fascinating opportunity to observe the curious power games that political leaders find so irresistible whenever they meet on the world stage. When Vladimir Putin welcomed David Cameron, Barack Obama, François Hollande and various other heads of state to the conference, he strategically positioned himself so that he would appear on the left, thereby exposing more of his right arm and making it look as though he was thoroughly in control.

Putin and a gesticulating David Cameron. Photograph: Grigory Dukor/Reuters

The handshake between Cameron and Putin was cordial and businesslike. Cameron managed to pull off his old trick of talking and gesticulating with his left hand during the handshake, casting himself in the role of speaker and Putin in the role of listener, and therefore making himself temporarily appear the more dominant of the two.

Putin and Obama were all smiles. Photograph: Ramil Sitdikov/EPA

The greeting between Obama and Putin was full of smiles but it was more reserved than normal. Obama also adopted the Cameron trick of talking and gesticulating during the handshake, but strangely he didn't pat Putin this time. This is something that Obama standardly does when he meets people, to show that he's the man in charge. Instead Obama extended his hand towards Putin but retracted it just before making contact. This shows that deep down he wanted to pat Putin but for some reason thought better of it. Was he unwittingly acknowledging the current political rift between the two men, or did he feel that under the circumstances it might be inappropriate to pretend he was in charge?

Obama reaches towards Putin's shoulder. Photograph: Sipa/Rex Features

After his handshake with Putin, Obama produced a little fitness display – he turned, walked away and jogged up the stairs leading into the building. Maybe he did this because he couldn't resist running up stairs, but it's more likely he figured that the world's eyes were still on him, and so took the opportunity to remind everyone how politically fit he is.