Why are non-Muslims not allowed to visit?

Maulana agla sawal Tariq Badar sahib ne bheja hai Lahore Pakistan se, aur unhon ne likha hai ke Today's lecture added another dimension to understand the issues in life as well as in the world and the creation plan of God, jazak Allah, my question is why non Muslims are not allowed to visit Mecca and Medina, and what is

the background of this law? Dekhiye, is se pehle main bata chuka hoon ke pehle aisa nahi tha, pehle sabhi log aate the, is ka saboot yeh hai ke Kaaba mein but pahunch gaya to mushrikeen to pohnchayen ge, but muhadd kaise but pohnchaye ga, kaba mein jo but pohncha kai so ki tadad mein to mushrikeen to thay, woh jo pohnchaya unhon ne, muhadd ko pohnchaye ga woh, to

yeh dekha gaya ke log is is azadi ko misuse karte hain, yaani yeh nahi kaha ke dekh kar chale jayen, wahan apna but rakh dete hain, woh but jo thay wahan kaba bohat chhote chhote thay, yaani bara bara abu lahore ki tarah nahi tha, woh aap jeeb mein rakh ke le ja sakte hain, aisa tha woh, jitne but thay kaba mein woh abu lahore ki tarah thay, nahi

thay bare bare, to adam jaye jeeb mein rakhe hue hain, wahan rakh ke chala gaya, to us ki precaution ke taur par is tajrube ke baad aisa kiya gaya, aur main samajhta hoon ke bilkul sahi sahi kiya gaya, warna aaj bhi wahi mamla baqi rehta, insaan ajeeb ghareeb makhlooq hai, azadi ko misuse karna jo hai us ki burai ko janta hi nahin. Okay, so we will end the session now, thank you.