Tradition early game warring?

[besset]

Currently playing a tradition game as Arabia on deity. My closest neighbours are Ethiopia( not a threat) and Japan. Japan went progress but has a lot of military units. Has also really close to my capital in pretty open terrain and his second city is like 6 or 7 tiles from my capital. What do you do in this situation? Take him out early or defend the rest of the game? I feel like he's too close to be friends with him in this game but still I have a lot of other things to build early game. We both get our UU at the same time too so I'm not sure how to approach this.

Edit: this is my start:

https://imgur.com/gallery/2rbYh9A

also save game if ya wanna check it/ try it for funsies 11/21 version:

 

[Minh Le]

As tradition, the capital will be too busy building wonders and stuff, so if you want early war, you would need a secondary city which has decent production and focus solely on producing military. If not, I recommend staying defensive with choke point and few units.

 

[tu_79]

Sell your excedents to Ethiopia and buy some units first. Then use a buffer city so they don't get near to your capital, with walls as soon as you can. Settle it best over a hill with a river facing Japan. Use terrain to your favor, chopp some forest where the Japanese could find cover.

Whatever you do, don't let your units die, don't risk them, fight safely, use condoms.

 

[besset]

My start: https://imgur.com/gallery/2rbYh9A

also save game if ya wanna check it/ try it for funsies 11/21 version: