Not sure why there are a thousand thumbs down on the good answers, 'ay?
Most everyone is right. You put an elderly dog, in with a baby. There is more energy there than you could believe. The older a dog gets the less likely it is that it will openly bond with a new pack member as quickly as they would have when they were five or six years old.
My twelve year old (female) husky STILL hasn't warmed up to my six year old German shepherd/Siberian husky mix, and we've had her since she was eight weeks.
Your assumption on the invasion of territory isn't correct, really. The elderly dog IS head of the doggy-household. Thats how it should work. If he doesn't want to play, he doesn't want to play. Two weeks isn't nearly a long enough time to expect them to be playing with each other, especially with an age difference THAT large.
When the puppy matures and loses some of his energy, he'll calm down and the older dog will be more likely to play. But right now, its like putting an elderly man with a walker next to a seven year old with a sugar stick. They aren't evenly matched.
So just give it time, don't allow the two of them to "argue" over you, they need to get your attention equally. There may be a jealousy issue later on if you prefer the puppy to the elderly dog, or vice versa.
Trainer, Vet Tech, Shelter Worker