why can't i repair in Israel my iphone 6 that i bought in US even when i still have insurance

Because they’re highly unlikely to have replacement USA models in stock. Apple and authorized service providers are generally only obligated to honor an iPhone warranty in the country of origin; one which came from an EU country or Switzerland is eligible anywhere within the region.

(152079)

If you have insurance then you need to make a claim with whomever you have that insurance with. Apple does not sell insurance. The do provide a manufacturers one year warranty, and up to an additional year extended warranty. Those warranties are not truly international and never have been. The do now, and always have, included the caveat that Apple may restrict warranty service to the country of original sale.